This paper presents, for the Queensland portion of the Rhaetian – Early Cretaceous Surat Basin, the results of a taxonomic-descriptive study of 89 palynological samples collected from three boreholes that intersected the succession containing the Gubberamunda Sandstone and the succeeding Orallo Formation, as well as the upper Westbourne Formation and the lower Mooga Sandstone, which respectively underlie and overlie this succession. This upper Westbourne Formation – lower Mooga Sandstone interval represents the most complete Late Jurassic – Early Cretaceous sedimentary succession in Queensland. It was sampled from: GSQ DRD 26, GSQ Roma 2 and GSQ Dalby 1, respectively located in the western, central, and eastern parts of the basin. The samples yielded a diverse palynoflora in which 212 taxa were identified, embracing both in-situ and reworked (latest Carboniferous – Early Jurassic) spores and pollen, as well as palynomorphs of algal, fungal, acritarch and unknown affinities. Formally included in this work is the previously unpublished taxonomy of McKellar, largely from the immediately preceding part of the Surat Basin succession, as its taxonomic nomenclature is critical to the current compilation. Herewith proposed (from both the current work and that of McKellar) are 27 new species, two new genera, 22 new combinations, ten emendations, the elevation of one subgenus to generic status, and the renaming of one species. From a biostratigraphic perspective, palynofloras from the upper Westbourne Formation and the lower Gubberamunda Sandstone are assigned to the informally defined ‘Retitriletes watherooensis association zone’, and palynofloras from the upper Gubberamunda Sandstone, Orallo Formation and lower Mooga Sandstone, to the Ruffordiaspora australiensis Interval Zone. The upper Westbourne Formation – lower Mooga Sandstone interval was deposited in lacustrine, floodplain and backswamp facies, with a flora that remained relatively stable, there being no major floristic turnover; it consisted of diverse ferns, conifers, lycopods, bryophytes, seed ferns, and a variety of ginkgoes, cycads, and/or gnetales. Humid, warm-temperate conditions are indicated by the flora’s climatic signature.

The Surat Basin of eastern Australia occupies an area of approximately 300,000 km2 in Queensland and New South Wales and is host to numerous economically significant resources (Figure 1; Exon 1976; Jell 2013). The basin’s succession embraces the Rhaetian Eddystone beds at its base, and the Albian Griman Creek Formation at its upper limit. As this succession was deposited in a predominantly terrestrial setting, spore-pollen biostratigraphy has been the primary method of dating and correlating its strata. Some isotopic dating of tuffs has also been conducted, complementing the biostratigraphy and assisting determination of the relationships of both the strata and their contained palynofloras to the Geologic Time Scale (e.g. Wainman, Hannaford, et al. 2018; Wainman, McCabe, et al. 2018; Cooling et al. 2021) The biostratigraphic approach has incorporated a number of detailed palynostratigraphic and taxonomic studies that have delineated, described, and documented palynomorphs and their stratigraphic ranges and assemblage associations across the basin (Figure 2). Key works, published by the Geological Survey of Queensland (GSQ), include those of de Jersey and Paten (1964) and Reiser and Williams (1969), both of which have described palynofloras recovered from the Lower Jurassic Precipice Sandstone, at the then-known base of the section [prior to the separate discoveries of both the older geographically-isolated and unconformity-bounded Rhaetian Eddystone beds and the Hettangian Chong beds; fig. 7.2 of McKellar in Jell (2013)]. The cited palynological studies further included the succeeding Evergreen Formation and lower Hutton Sandstone, with de Jersey and Paten also describing some species from the ensuing ‘Rosewood Coalfield’ (Walloon Coal Measures). These publications were followed at GSQ by the work of McKellar (1974) who detailed palynofloras from the upper Evergreen Formation, Hutton Sandstone and lower Walloon Coal Measures, extending the published record of study into the Middle Jurassic strata. His 1998 PhD thesis and associated ‘in press’ manuscript (see discussion below on the latter) detail palynofloras from the mid-Evergreen Formation through to the top of the Westbourne Formation, further extending assessment of the Surat Basin higher into the Upper Jurassic section. Both his thesis and his ‘in press’ manuscript have been cited by a number of authors, with publication of the latter being withdrawn at pre-publication stages by GSQ, both as: (1) a GSQ publication (e.g. referred to by Sajjadi and Playford 2002a, 2002b), because digital publication, pursued by GSQ, was, and remains, unacceptable to the International Code of Botanical Nomenclature (now the International Code of Nomenclature for Algae, Fungi, and Plants); and (2) subsequently as a monograph in the Memoir Series of the Australasian Association of Palaeontologists, Geological Society of Australia (e.g. cited by Ribecai 2007; Jell 2013; Cooling 2020). The latter resulted from a changing focus by GSQ, including discontinued direct and indirect support, among other subdisciplines, for palynology, paleontology and biostratigraphy; this also greatly impacted the progress of the current work on the upper Westbourne Formation – lower Mooga Sandstone succession.

However, McKellar’s (1998) PhD thesis and associated unpublished manuscript have permitted sound, intrabasinal and interbasinal, biostratigraphic assessment of the Jurassic succession. His biostratigraphic correlations, employed in the compilation of stratigraphic charts, have been extensively utilised in unpublished exploration-industry reports and in published literature, the latter also including that of the Geological Survey of Queensland (e.g. Draper 2002; Scott et al. 2007; Cook et al. 2013, fig. 7.2). Also cited by several authors have been McKellar’s new taxa, both generic and specific, which were fully described/detailed by him, together with many new generic-specific recombinations, etc. These citations, which were invalidated by non-publication, are herein compiled in the synonymy lists of the taxa in question, with their attendant nomenclatural validation. In providing the necessary platform to overcome this major taxonomic predicament, this current work highlights the significance that this publication plays in correcting these citation and nomenclatural anomalies, but with authorship of the herein-validated taxa predominantly now being ascribed to both the current authors (JJC & JLMcK). Taxonomic stability has thus prevailed, providing support for comprehensive assessment of the palynomorphs encountered in the present study of the Jurassic–Cretaceous transition in the Surat Basin.

For eastern Australia’s Lower Cretaceous succession, the studies of Burger (1974, 1980), working as a palynologist for the Bureau of Mineral Resources (BMR; subsequently the Australian Geological Survey Organisation/AGSO, and now Geoscience Australia/GA), documented palynofloras from the Mooga Sandstone and the overlying Surat Basin formations. Between these two sets of studies by GSQ and the BMR/AGSO (GA), palynofloras of the Gubberamunda Sandstone and Orallo Formation went undescribed. The purpose of the current work on the upper Westbourne Formation – lower Mooga Sandstone interval is to bridge this gap in knowledge of the palynological record in the Surat Basin, embracing the Jurassic–Cretaceous transition.

Although the taxonomic-descriptive appraisal presented here (Main Text) and in the Supplemental Appendix comprises both the current study [incorporating the PhD thesis work of Cooling (2020)] and the above-cited, unpublished work of McKellar, that part submitted below encompasses taxa for which formal published treatment of nomenclature is required by the International Code of Nomenclature for Algae, Fungi, and Plants/ICNAFP (Turland et al. 2018). Contrastingly, taxa recorded (in this study of the System transition) for which there has been no change in formal nomenclature are relegated to the Supplemental Appendix, accompanied there by a more comprehensive set of photographic plates. Included there also is a list of all samples taken from the three boreholes studied (Supplemental Table 3), together with attendant species range charts. The taxonomic-descriptive appraisal of McKellar (1998, unpublished PhD thesis), together with his sample details and borehole locations, species range charts, ‘Q’ catalogue numbering (for holotypes), etc., are available from the Library of The University of Queensland, Library Services (Queensland Department of Environment, Science and Innovation), and can be fully downloaded from ResearchGate.

From a biostratigraphic perspective, also referred to herein (under both Results and Discussion) is the ‘Retitriletes watherooensis association zone’ of McKellar (1998). The concept of an ‘Association Zone’, as a new type of biostratigraphic unit, was introduced by McKellar, together with six association zones defined thereunder (for the late Early – Late Jurassic succession), including the ‘R. watherooensis association zone’ [as described by Backhouse (1978) and modified in definition by McKellar].

The ‘Retitriletes watherooensis Association Zone’ was referred to by Sajjadi and Playford (2002a, 2002b, Text-fig. 2) as ‘McKellar (in press, Geol. Surv. Qld.)’ in their study of the Late Jurassic – earliest Cretaceous succession in the Eromanga Basin (adjacent to, and interconnected with, the Surat Basin to its west), together with the five other zones proposed by McKellar under his new ‘Association Zone’ concept. The latter five ‘Association Zones’ have also been specifically referred to by Ribecai (2007, 8, fig. 4) in a study of Early Jurassic miospores from South Victoria Land, Antarctica.

McKellar’s ‘association zones’, together with de Jersey and McKellar’s (2013) new Toripustulatisporites hokonuiensis Association Zone (Hettangian), were subsequently referenced by Jell (2013, 525, fig. 7.2), the former being cited as ‘McKellar, in press: Memoirs of the Australasian Association of Palaeontologists’, and the latter as ‘de Jersey and McKellar, in press: Palynology’. As the Geological Survey of Queensland did not follow through with publication of McKellar’s reviewed-and-accepted biostratigraphy and its attendant palynological compilation, the concept of the ‘Association Zone’ was then published by de Jersey and McKellar (2013), and, therewith, the Toripustulatisporites hokonuiensis Association Zone. The latter zone, dated by correlation with New Zealand, assisted comprehension of the complexity of the Triassic–Jurassic transition in eastern Australia, an assessment that can be derived only from palynological and biostratigraphic studies.

The association zone concept was further expanded by Bomfleur et al. (2014) in their study of latest Triassic and Early Jurassic material from north Victoria Land, East Antarctica (Transantarctic Mountains) with institution of the Norian–Rhaetian Polycingulatisporites crenulatus Association Zone that encompasses the Norian P. crenulatus Association Subzone and the succeeding Rhaetian Foveosporites moretonensis Association Subzone.

Although McKellar’s ‘six ‘association zones’ were referred to in publication by Jell (2013) in the Geological Survey of Queensland’s Geology of Queensland publication in which they were employed for interbasinal correlation of Queensland’s Mesozoic sedimentary basins, the zones currently have informal status, as they have not been validly defined and published. This remains the case for the ‘Retitriletes watherooensis association zone’, where McKellar’s unpublished definition is referred to and employed in this work.

For the classification of taxa, the pregenetic scheme adopted here and in the Supplemental Appendix is outlined below. However, at the generic level, to avoid unnecessary duplication of systematic and attendant detail between this main part of the publication (Main Text) and the Supplemental Appendix, the latter provides details of type species and generic synonymies, except where a genus is dealt with only in the Main Text or has been emended, in which case type-species and synonymy details are given below.

In terms of photomicrography (the equipment employed for this J–K transition study being indicated below), the photomicrographic plates contain a mixture of colour images (this study) and grayscale images (McKellar 1998), but only in this Main Text (not in the plates associated with the Supplemental Appendix). This resulted from the necessity, at a late stage, to import into this publication the new taxa, nomenclatural changes, and the attendant (grayscale) images of the cited author, with the aborted publication of McKellar’s work and without any opportunity to provide colour images. An additional necessity to avoid further photographic-plate restructuring in the Main Text is the inclusion below of five new generic-specific recombinations for which the associated figured specimens are shown only in the supplemental plates (Supplemental Appendix).

Paleogeographic reconstructions for the time interval (Tithonian–Hauterivian) here associated with deposition of the Westbourne Formation – Mooga Sandstone succession maintain that: (1) the intracratonic Surat Basin was located between 50 and 80 degrees South latitude in the southeastern sector of the rifting Gondwanan landmass; (2) this landmass was rotated such that the Greater Australian region was orientated about 90 degrees relative to its current position (Embleton 1984; Bradshaw and Yeung 1992; Scotese 1998; Scotese 2001; McLoughlin 2001; Veevers 2006; Klootwijk 2009; Torsvik and Cocks 2019); and (3) the basin at that time was situated several hundred kilometers inland from the coast (e.g. Bradshaw and Yeung 1992; Waschbusch et al. 2009).

Previous palynological studies of the overlying and underlying formations of the Surat Basin and adjoining Eromanga Basin have suggested a humid and cool to warm temperate climate for the region (Burger 1980; McKellar 1996; McKellar 1998, 199; Sajjadi and Playford 2002a, 2002b). Based on evidence from across the continent, the Late Jurassic and earliest Cretaceous flora of Australia was dominated, if not in diversity, then in biomass, by conifers, particularly those of the Araucariaceae and Podocarpaceae, with members of the Cheirolepidiaceae, Taxodiaceae and Pinaceae playing a lesser role (Anderson et al. 1999; Truswell et al. 1999; Grant-Mackie et al. 2000; Sajjadi and Playford 2002a, 2002b). Forest understories and open regions were inhabited by diverse ferns, tree ferns, seed ferns (Pteridospermatophyta), liverworts, mosses, horsetails (Equisetopsida), bennettitales and pentoxylales (Gould 1975; Burger 1980; Dettmann et al. 1992; McKellar 1998; Sajjadi and Playford 2002a, 2002b; Turner et al. 2009).

From a stratigraphic perspective, the Westbourne Formation has been recognised across the Surat and adjoining Eromanga basins and consists of interbedded carbonaceous mudstone, siltstone, and fine-grained sandstones. These strata are interpreted as having been deposited in a lacustrine to lacustrine-deltaic setting (Exon 1976; Green 1997). The formation conformably overlies the Springbok Sandstone and has been considered to be Kimmeridgian – early Tithonian in age (McKellar 1998; Cook et al. 2013; Wainman, Hannaford, et al. 2018).

The Gubberamunda Sandstone is largely conformable on the underlying Westbourne Formation, but some localised disconformities exist. Consisting of thickly bedded to massive, poorly sorted, medium- to coarse-grained sandstones interbedded with thinly bedded siltstones, and carbonaceous mudstones, it has been assigned a Tithonian–Berriasian age (Cook et al. 2013; Cooling et al. 2021). The formation was deposited in a fluvial environment of braided and meandering streams (Exon 1976; Green 1997).

The Orallo Formation conformably overlies the Gubberamunda Sandstone and comprises medium- to coarse-grained sandstone interbedded with siltstone, carbonaceous mudstone, and bentonitic tuffs. It was deposited by a lower-energy fluvial system compared to that of the underlying Gubberamunda Sandstone (Exon 1976; Green 1997). The formation has been assigned a late Berriasian to early Hauterivian age (Cook et al. 2013; Cooling et al. 2021). The Mooga Sandstone conformably overlies the Orallo Formation in most parts of the basin, but there are some areas with localised disconformity between the two units. The lower part of the Mooga Sandstone consists of sandstones interbedded with clayey sandstone, siltstone and mudstone; it was deposited by braided to meandering streams (Exon 1976; Green 1997). The unit has been interpreted as being of Hauterivian age (Cooling et al. 2021).

The following information on the upper Westbourne Formation to lower Mooga Sandstone interval has been derived from the PhD thesis work carried out by Cooling (2020).

Sampling

Samples from the Gubberamunda Sandstone and overlying Orallo Formation, together with samples from the upper part of the underlying Westbourne Formation and lower part of the overlying Mooga Sandstone, served as the principal basis for this palynological study. They were collected from three GSQ stratigraphic boreholes, GSQ DRD 26, GSQ Roma 2 and GSQ Dalby 1, held at the Exploration Data Centre (Department of Resources, Brisbane, Queensland). Supplemental Table 3 lists the palynological samples taken and includes brief descriptions of sample lithology and palynomorph yield, together with the attendant palynological microslide numbers.

GSQ DRD 26

GSQ DRD 26 (GSQ borehole ID number: 512) was drilled in 1968 in the northwestern Surat Basin (-26.381766, 148.617785 GDA94) as a fully cored borehole. It intersected, at the indicated depths, the upper Westbourne Formation (217.6–259.2 m), Gubberamunda Sandstone (168.2–217.6 m), Orallo Formation (29.9–168.2 m), and the lower Mooga Sandstone (13.4–29.9 m) (Gray 1972). Six samples were taken from the Westbourne Formation, seven from the Gubberamunda Sandstone, 13 from the Orallo Formation, and three from the Mooga Sandstone (Supplemental Table 3).

GSQ Roma 2

GSQ Roma 2 (GSQ borehole ID number: 534) was drilled in 1969 in the middle of the northern Surat Basin (-26.348430, 149.734427 GDA94) as a fully cored borehole. It intersected the upper Westbourne Formation (256.9–274.5 m), Gubberamunda Sandstone (111–256.9 m), Orallo Formation (31.4–111 m), and the lower Mooga Sandstone (18.9–31.4 m) (Gray 1972; OGIA 2015; personal observations). Five samples were taken from the Westbourne Formation, 21 from the Gubberamunda Sandstone, 11 from the Orallo Formation, and three from the Mooga Sandstone (Supplemental Table 3).

GSQ Dalby 1

GSQ Dalby 1 (GSQ borehole ID number: 1486) was drilled in 1980 in the northeastern Surat Basin (-27.339258, 149.734427 GDA94) as a fully cored borehole. It intersected 857.7 m of the Surat Basin succession, including the Westbourne Formation (192.4–390 m), the Gubberamunda Sandstone (109.5–192.4 m), and the Orallo Formation (15–109.5 m) (Clark and Cooper 1985). Five samples were taken from the uppermost part of the Westbourne Formation, five from the Gubberamunda Sandstone, and ten from the Orallo Formation (Supplemental Table 3).

Processing and analyses

All palynological samples collected were processed and all yielded sufficient palynomorphs to reach a count of 300 specimens (Supplemental Table 3). Of the 89 samples taken, 28 from GSQ DRD 26 and 32 from GSQ Roma 2 were used for detailed study of species morphology and semi-qualitative, assemblage-composition analyses. Fifteen samples from GSQ Dalby 1 were similarly studied, but with taxa being recorded in each assemblage only on a presence-or-absence basis. Another fourteen samples (indicated by an asterisk in Supplemental Table 3) from across the three boreholes were employed to provide only supplementary morphological data or for photographic purposes.

Samples were processed by Santos Ltd’s palynological laboratory, which broadly followed the methodology of Phipps and Playford (1984). The samples were broken into pea-sized pieces before undergoing digestion with HCl and HF. The residues were filtered to remove anything smaller than 10 µm or larger than 140 µm. To separate any remaining mineral matter, a heavy liquid of sodium polytungstate, prepared to a specific gravity of 2.1 SG, was used. For each sample, a kerogen slide was produced and evaluated for palynomorph content relative to slide debris (non-palynomorph organic matter).

When samples provided satisfactory kerogen slides, one or two additional kerogen slides were prepared, while overly dark samples, or samples that contained too much amorphous organic matter or pyrite, were oxidised using 70% HNO3 and KClO3. Samples that still had a low proportion of palynomorphs relative to other matter then underwent a second specific gravity separation at 1.65 SG.

Light microscopy, photography, and palynological-data collection

The present study employed an ‘Olympus’ BX53 binocular microscope and attached Olympus DP26 camera. Over six thousand photomicrographs were taken to assist the identification and delineation of species.

Repository, terminology and descriptive procedure

Sample slides and residues have been lodged with the Queensland Museum, Brisbane. The morphologic terminology used in the following systematic descriptions is taken from the glossaries published by Dettmann (1963), Kremp (1968), Punt et al. (2007), and Smith and Butterworth (1967). Dimensional terms for bisaccate pollen are as described by Foster (1979, fig. 17). Synonymy listings are here used to document the nomenclatural history of taxa, as well as to provide reference to key papers on the various taxa. Listed under ‘Previous records’ are representative occurrences of taxa in time and space with a focus on Australian occurrences, particularly occurrences from eastern Australia.

Descriptions and measurements of palynomorphs are based on multiple specimens. The measurements provided are the minimum, maximum and arithmetic mean (in parentheses) of all measured specimens and indicate if sculptural height is included or not. Primarily, measurements of apiculate spores are exclusive of projecting sculpture, while measurements of reticulate spores include the reticulum. The equatorial dimensions of non-circular trilete spores are based on the greatest of the three measurements from an apex to the centre of the opposite side. Where possible, known botanical affinities are given. This information is not available for all taxa due to the difficulties in reliably correlating fossilised dispersed spores and pollen with their parent plants. New species have been erected and are described based on at least 15 adequately preserved specimens. Many existing species are also re-described. Taxa recorded by a single specimen or by an insufficient number of specimens to be described as a new species are named Genus sp. A, Genus sp. B, etc.

Nomenclature and taxonomic classification

In suprageneric classification of sporae dispersae, both in this Main Text and in the Supplemental Appendix, the scheme proposed by Dettmann (1963) is adopted here for the Anteturma PROXIMEGERMINANTES Potonié 1970 (Sporites), together with certain modifications conceived by Smith and Butterworth (1967); and, for the Turma MONOLETES Ibrahim 1933, the classification of Balme (1970), is adhered to. For the Anteturma VARIEGERMINANTES (Pollenites), the subdivisions of Potonié (1966, 1970) and Maheshwari (1974) are followed.

The stratigraphic ranges of selected taxa are shown in Figure 3, Figure 4 and Figure 5, respectively for GSQ DRD 26, GSQ Roma 2 and GSQ Dalby 1. Detailed range charts, presenting quantitative abundances of each in-situ taxon by percentage and arranged in order of up-hole appearance, are provided in Supplemental Figures 2, 3 and 4; reworked taxa are included therein.

Included collectively in the ‘Systematic descriptions’ section below (Main Text) and in the equivalent section in the Supplemental Appendix, are the 212 individual taxa that were identified in the PhD study of Cooling 2020. Of the in-situ taxa, there are 147 spore taxa from 64 genera, 28 pollen taxa from 17 genera, and 12 taxa of non-miospore affinity. In addition, 23 taxa are recognised as having been reworked from older strata. However, this Main Text, in jointly embracing and validating the unpublished work of McKellar (1998), presents 27 new species, two new genera, 22 new combinations, 10 emendations, the elevation of one subgenus to generic status, and the formal renaming of one species.

The palynofloral assemblages recovered from samples in the study of Cooling are broadly similar in their overall composition, particularly at the generic level. Based on the samples from GSQ DRD 26 and GSQ Roma 2, for which assemblage counts were produced, spores of Cyathidites, Osmundacidites and Retitriletes all individually average approximately 10% of the attendant assemblages. Spores and pollen of Alisporites, Araucariacites, Callialasporites, Neoraistrickia, Rugulatisporites and Verrucosisporites each average between three and six percent of assemblages. Biretisporites, Botryococcus, Cibotiidites, Classopollis, Concavissimisporites, Contignisporites, Gleicheniidites, Inaperturopollenites, Laevigatosporites, Microcachryidites, Perinopollenites, Phlebopterisporites, Podocarpidites, Todisporites and Trachysporites all each average between one and three percent of overall assemblages. Palynomorphs from all other genera encountered in this study average less than one percent each of overall assemblages.

The assemblages appear to be almost, if not entirely, terrestrial in character, with the only indication of any marine inter-connectivity being rare occurrences of Micrhystridium from the upper Westbourne Formation, Gubberamunda Sandstone and the basal Orallo Formation.

Samples from the upper Westbourne Formation and the overlying lower Gubberamunda Sandstone in GSQ DRD 26 and the overlying lower to mid-Gubberamunda Sandstone in GSQ Roma 2 and GSQ Dalby 1 are assignable to the informally defined ‘Retitriletes watherooensis association zone’ (see Introduction for discussion on the zone’s history and status). This determination, per the definition of McKellar (1998), is based on the presence of the zonal index species, Retitriletes watherooensis, and the absence of any specimens of Ruffordiaspora spp. The first appearance of Ruffordiaspora australiensis (at 145.09 m in GSQ Dalby 1, 158.6 m in GSQ Roma 2, and 212.37 m in GSQ DRD 26) marks the lower boundary of the Ruffordiaspora (‘Cicatricosisporites’) australiensis Interval Zone, as described by Helby et al. (1987). No specimens of Foraminisporis wonthaggiensis, the index taxon of the succeeding F. wonthaggiensis Interval Zone (Helby et al. 1987), were recognised in any of the study samples.

Spores

Anteturma PROXIMEGERMINANTES R. Potonié 1970 

Turma TRILETES Reinsch emend. Dettmann 1963 

Suprasubturma ACAVATITRILETES Dettmann 1963 

Subturma AZONOTRILETES Luber emend. Dettmann 1963 

Infraturma LAEVIGATI Bennie & Kidston emend. R. Potonié 1956

Genus Obtusisporis (Krutzsch) Pocock 1970 

(see Supplemental Appendix for type species and other details)

Obtusisporis modestus (McKellar) McKellar & Cooling comb. nov.

Plate 1, fig. 1; Supplemental Plate 1, figs 11–15

Synonymy.

1967 Undulatisporites sp. cf. U. undulapolus Brenner; Norris, 87; pl. 10, figs 6–7.

1974 Biretisporites modestus McKellar, 4; pl. 1, figs 1–4.

1998 Obtusisporis modestus (McKellar) McKellar*, 44–45; pl. 1, figs 15–18.

2002a  Obtusisporis modestus (McKellar) McKellar, ‘in press’; Sajjadi and Playford, 21; pl. 1, fig. 17.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ e.g. Sajjadi and Playford (2002a, above); see explanatory note in Introduction].

Dimensions. Equatorial diameter (60 specimens) 16.5 (30) 47 μm.

Remarks and comparisons. The species was placed in combination with Obtusisporis (Krutzsch) emend. Pocock 1970 as the distally situated ‘irregular pits and channels’ (McKellar 1974, 4) appear to occur, not at the surface of the exine, but internal thereto. They are closely comparable with the ‘vacuoles and spaces’ said to form in Obtusisporis between the loosely adherent and readily separated nexinal and sexinal layers (Pocock 1970, 35). However, there is no clear indication that the exine of O. modestus is two-layered; this has not been demonstrated either in the type species (Krutzsch 1954, 297) or in other species assigned to the genus.

Occurrence (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Jurassic to earliest Cretaceous of Queensland (McKellar 1974; McKellar 1998; Sajjadi and Playford 2002a, 2002b).

Infraturma APICULATI Bennie & Kidston emend. Potonié 1956

Subinfraturma GRANULATI Dybová & Jachowicz 1957

Genus Osmundacidites Couper 1953 

(see Supplemental Appendix for type species and other details)

Osmundacidites injunensis McKellar & Cooling sp. nov.

Plate 1, figs 2–8; Supplemental Plate 1, figs 23, 24

Synonymy.

1998 Osmundacidites injunensis McKellar*, 49–50; pl. 2, figs 8–13.

*New species: Validated in publication here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Diagnosis. Spores radial, indistinctly trilete, generally appearing alete. Amb subcircular. Laesurae poorly developed when present, approximating spore radius in length. Exine <1–1.5 μm thick; distally and equatorially granulate-verrucate, and also partly conate-subbaculate in some specimens. Grana and verrucae <1–2.5 μm high; bases subcircular to elongate or irregular in outline, <1–5 μm in diameter. Coni and subbacula 1–4 μm high, 1–3.5 μm in basal diameter. Sculptural elements closely spaced, discrete (<1–2 μm apart) or partly coalescent. Proximal surface similarly sculptured in equatorial areas, otherwise laevigate(?), scabrate or finely granulate.

Dimensions. Equatorial diameter (81 specimens) 22 (37) 55 μm (McKellar 1998). Equatorial diameter (19 specimens) 28.5 (36.5) 57 μm (this study).

Holotype. Slide A1971/3, V54/2; Q254; Plate 1, figs 2–3.

Type locality. GSQ Roma 8, 787.59 m, Hutton Sandstone.

Etymology. Named after the Injune Creek Group.

Remarks and comparisons. The species is readily distinguished from other granulate-verrucate-rugulate spores in the Surat Basin by its small size, reduced proximal sculpture, and generally indistinct laesurae. Osmundacidites wellmanii Couper 1953 is finely granulate-rugulate proximally and distally.

Occurrence (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Jurassic of the Surat Basin (McKellar 1998).

Subinfraturma VERRUCATI Dybová and Jachowicz 1957

Genus Converrucosisporites Potonié & Kremp 1954 

(see Supplemental Appendix for type species and other details)

Converrucosisporites parvitumulus McKellar & Cooling sp. nov.

Plate 1, figs 9–14; Supplemental Plate 2, figs 1–2

Synonymy.

2009 Converrucosisporites sp. cf. C. parvitumulus McKellar; Mantle, 28; pl. 2 fig. 2.

1998 Converrucosisporites parvitumulus McKellar*, 51–52; pl. 2, figs 14–18.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Mantle 2009, 28; plate 2, figure 2: for depiction of Converrucosisporites sp. cf. C. parvitumulus); see explanatory note in Introduction].

Diagnosis. Spores radial, trilete. Amb subtriangular, apices rounded, sides straight to weakly convex (or very rarely with one or two weakly concave sides). Laesurae moderately distinct, straight, extending 0.5–0.8 spore radius, often enclosed within weakly raised commissures. Exine <1–1.5 μm thick, sculptured with low, ±subhemispherical grana-verrucae (<1–2 μm high) borne on subcircular to slightly elongate bases <1–4.5 μm in diameter (average ca. 1.5–2 μm). Sculptural elements irregularly distributed, discrete (spaced up to 5.5 μm apart) or partly coalescent. Exine otherwise laevigate or finely and imperceptibly granulate-rugulate. Proximal sculpture sometimes reduced, rarely aligned along laesurate margins.

Dimensions. Equatorial diameter (40 specimens) 27 (36) 51 μm; polar diameter (8 specimens) 29 (33) 41 μm (McKellar 1998). Equatorial diameter (35 specimens) 23.5 (34) 46 μm (this study).

Holotype. Slide A70/3, O35/0; Q261; Plate 1, figs 12–14.

Type locality. GSQ DRD 26, 155.02 m, Orallo Formation.

Etymology. Latin: parvus-a-um, small; tŭmŭlus-i (m), mound, hill.

Remarks and comparisons. The species is closely comparable with Lophotriletes verrucosus Schulz (1967 p. 561, pl. 2, figs 12–14; from the Rhaetian and Toarcian of Germany), which is distinguished by its concavely subtriangular amb. Close comparison can also be made with spores recorded as Leptolepidites sp. from the Rhaetian of northeastern France and southern Luxemburg (Schuurman 1977 p. 187, pl. 3, fig. 7).

The species is readily distinguished from other verrucate spores observed in this study by the well-separated, perfectly semi-hemispherical verrucae on an otherwise laevigate surface. This produces a ‘polka-dot’ like appearance.

Occurrence (Cooling2020 ). Rare to uncommon in the upper Westbourne Formation, Gubberamunda Sandstone and Orallo Formation, rare and sporadic lower Mooga Sandstone.

Previous records. Jurassic and Early Cretaceous of the Surat Basin (McKellar 1998).

Converrucosisporites pricei McKellar & Cooling sp. nov.

Plate 1, figs 15–21; Supplemental Plate 2, figs 3–4

Synonymy.

2002a  Converrucosisporites pricei McKellar ‘in press’*; Sajjadi and Playford, 28; pl. 2, figs 12–13.

1998 Converrucosisporites pricei McKellar*, 52–52; pl. 2, fig. 19; pl. 3, figs 1–6.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002a, above); see explanatory note in Introduction].

Diagnosis. Spores radial, trilete. Amb convexly subtriangular to ± subcircular, with irregular outline. Laesurae distinct, straight to weakly sinuous, 0.7–<1.0 spore radius; enclosed within elevated, equatorially tapering, membranous lips (2–9 μm high at pole) arising from weakly thickened laesurate margins. Exine 2–3 μm thick, verrucate or verrucate-granulate. Sculptural elements 1–4.5 μm high, rounded to subhemispherical in profile, rarely with granulate crests; bases discrete to partly coalescent, spaced up to 7 μm (usually 1–2 μm) apart, subcircular (infrequently subpolygonal) to elongate in outline, 1–7.5 μm in maximum diameter. On proximal hemisphere, sculpture reduced or absent in polar-subpolar areas, sometimes indefinitely aligned along laesurate margins.

Dimensions. Equatorial diameter (26 specimens) 45 (63) 91 μm; polar diameter (8 specimens) 49 (59) 68 μm (McKellar 1998). Equatorial diameter (7 specimens) 34 (51) 73 μm (this study).

Holotype. Slide A66/2, U59/0; Q262; Plate 1, Fig. 15.

Type locality. GSQ DRD 26, 177.06 m, Gubberamunda Sandstone.

Etymology. After P.L. Price, for his contribution to eastern and central Australian palynostratigraphy.

Remarks and comparisons. In the assemblages studied here, specimens of Converrucosisporites pricei McKellar & Cooling sp. nov. are often preserved with an oblique compression which can hinder identification, as the spore amb or laesurae are often partially obscured. Converrucosisporites pricei is convexly subtriangular-subcircular compared to Concavissimisporites verrucosus (Delcourt & Sprumont) Sajjadi & Playford, which has concave sides. Converrucosisporites parvitumulus has more dispersed and finer verrucae as well as a thinner exine. Spores of Foraminisporis Krutzsch 1959, which are often also circular or subcircular, are cingulate. Foraminisporis asymmetricus (Cookson & Dettmann) Dettmann 1963 has verrucae with commonly polygonal basal outlines, while F. sp. cf. F. tribulosus Playford & Dettmann 1965 can generally be distinguished by its less well developed laesurae, in addition to the presence of a cingulum.

Occurrence (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Late Jurassic and Early Cretaceous of Queensland (McKellar 1998; Sajjadi and Playford 2002a).

Genus Concavissimisporites (Delcourt & Sprumont) emend. McKellar & Cooling

Synonymy.

1955 Concavissimisporites Delcourt & Sprumont, 25.

1961 Lygodium Swartz 1801; Bolkhovitina (pars), 74.

1961 Lygodium Swartz 1801; Ivanova (pars) in Samoilovitch and Mchedlishvili, 90.

1962 Concavisporites Pflug 1953; Pocock (pars), 46.

1963 Concavissimisporites Delcourt & Sprumont emend. Delcourt et al. pp.284–285.

1964 Concavissimisporites Delcourt & Sprumont emend. Delcourt et al.; Singh, 76–77.

1964 Concavissimisporites Delcourt & Sprumont emend. Delcourt et al.; Pocock, 181.

1964 Maculatisporites Döring, 1099.

1964 Tuberositriletes Döring (pars), 1103–1104.

1965 Concavissimisporites Delcourt & Sprumont; Döring (pars) pp.31–35.

1987 Concavissimisporites Delcourt & Sprumont emend. Fensome (pars), 18–19.

1998 Concavissimisporites Delcourt & Sprumont emend. McKellar*, 58.

*Emendation: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction). Compare remarks of Sajjadi and Playford (2002a, 25) on the circumscription of the genus vs the emendation given here and by McKellar (1998).

Type. Concavissimisporites verrucosus Delcourt & Sprumont emend. McKellar & Cooling; original designation.

Emended diagnosis (after McKellar 1998). Spores radial, trilete. Amb subtriangular, apices rounded, sides straight to strongly concave, rarely convex. Laesurae distinct, long; margins generally elevated (obliquely inclined) and lipped. Exine of uniform thickness. Sculpture comprehensive, uniformly developed, verrucate to finely granulate (subgranulate).

Remarks and comparisons. The generic diagnosis has been extended to incorporate granulate (and subgranulate) sculpture, following the informal circumscriptions of Pocock (1964) and Singh (1964), as well as the distinctive laesurate features common to C. verrucosus [Delcourt et al. 1963, pl. 42, figs 5–6 (holotype)] and other related species herein and elsewhere recorded under the genus (see below). These haplotypic features (namely obliquely elevated and lipped laesurate margins) are generally characteristic of Concavissimisporites and a number of other genera including Cyathidites (Couper), Impardecispora Venkatachala et al. Trilobosporites Pant ex Potonié, Pilosisporites Delcourt & Sprumont, and Baldurnisporites Delcourt & Sprumont (compare Sajjadi and Playford 2002a). So constructed, they commonly give rise to a very characteristic gape of the trilete mark.

Concavissimisporites and Impardecispora are closely allied and morphologically intergradational, the latter being distinguished only by its apically differentiated sculpture (also see Dörhöfer and Norris 1977). This observation accords with the contrasting taxonomic approach of some authors, who have attributed apically and non-apically differentiated spores to the same genus [namely Lygodium Swartz (Bolkhovitina 1961; Ivanova in Samoilovitch & Mchedlishvili 1961) and Concavissimisporites (Döring 1965; Fensome 1987)].

Cyathidites is differentiated by its laevigate exine, although Delcourt and Sprumont’s (1955) original diagnosis of Concavissimisporites (compare Delcourt et al. 1963) also catered for unsculptured spores. Trilobosporites is valvate. Baldurnisporites encompasses azonate spores with an apically differentiated, reticulate sculpture. Converrucosisporites Potonié & Kremp 1954 lacks the laesurate features associated with the above genera (as does Granulatisporites Ibrahim emend. Potonié & Kremp 1954) and is employed to encompass generally subtriangular (verrucate) spores, its type species, Converrucosisporites triquetrus (Ibrahim) Potonié & Kremp, being convexly subtriangular. Concavisporites Pflug, in possessing an essentially smooth exine and a kyrtome, is a likely synonym of Dictyophyllidites Couper (compare Pocock 1962, 47).

Affinity. Schizaeaceae, Dicksoniaceae and Cyatheaceae (Couper 1958; Dettmann 1963; Balme 1995).

Concavissimisporites verrucosus (Delcourt & Sprumont) emend. McKellar & Cooling

Plate 1, figs 22–28; Supplemental Plate 2, figs 14–15, 22–23

Synonymy.

1955 Concavissimisporites verrucosus f. verrucosus Delcourt & Sprumont, 26; pl. 2, fig. 1a.

1955 Concavissimisporites verrucosus f. crassatus Delcourt & Sprumont, 26; pl. 2, fig. 1b.

1958 Concavisporites variverrucatus Couper, 142; pl. 22, figs 4–5.

1962 Concavisporites verrucosus (Delcourt & Sprumont) Pocock, 46–47; pl. 5; figs 73–74.

1962 Concavisporites verrucosus (Delcourt & Sprumont) Pocock var. minor Pocock, 47; pl. 5, figs 75–76, (?)figs 77–78 (nom. nud.).

1963 Concavissimisporites verrucosus Delcourt & Sprumont emend. Delcourt et al. p. 285; pl. 42, figs 5–7.

1963 Concavissimisporites crassatus (Delcourt & Sprumont) Delcourt et al. p. 285; pl. 42, figs 9–11.

1963 Concavissimisporites minor (Pocock) Delcourt et al. p. 286 (nom. nud.; no designated holotype).

1969 Converrucosisporites variverrucatus (Couper) Norris, 585; pl. 102, fig. 19.

1998 Concavissimisporites verrucosus (Delcourt & Sprumont) emend. McKellar*, pl. 4, figs 5–13; pl. 5, figs 1–2.

For additional synonymy, see Srivastava (1975, 32).

*Emendation: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished manuscript, the latter cited by Sajjadi and Playford (2002a) as McKellar (‘in press’; see explanatory note in Introduction).

Emended diagnosis. Spores radial, trilete. Amb subtriangular, apices rounded, sides straight to concave. Laesurae distinct, straight, extending 0.6–0.8 spore radius, occasionally bifurcating at equatorial extremities; enclosed within elevated, equatorially tapering, membranous lips (up to 2.5, rarely 5 μm high at pole; generally not preserved), and commonly accompanied by a ‘margo’ (obliquely inclined, bordering exine giving rise to lips) which narrows abruptly near equatorial extremities of suturae; laesurate margins with tendency to gape. Exine 1.5–3 μm thick, sculptured with discrete to coalescent grana and/or verrucae <1–3 μm high; bases subpolygonal, subcircular or elongate, <1–7 μm in maximum diameter, spaced up to 5.5 μm apart. Sculptural elements rounded to subhemispherical in profile, comprehensively developed, sometimes weakly aligned along laesurate margins.

Dimensions. Equatorial diameter (40 specimens) 37.5 (67.4) 98 μm.

Remarks and comparisons. Supporting the views expressed by Pocock (1962, 46–47), C. verrucosus and C. variverrucatus (Couper) Brenner are considered to be representative of a single species displaying continuous variation in overall size of individuals, and in the size, basal outline, and spacing of sculptural elements (compare: Delcourt et al. 1963, 285–286; Fensome 1987). Finer taxonomic subdivision of this morphologically broad spore complex, the framework of which is presently available (see synonymy), creates ambiguous and extremely diffuse interspecific boundaries. Moreover, in the sections examined here, there is no apparent justification, on the basis of relative stratigraphic occurrence of the respective variants, for the adoption of such refined and essentially impractical specific categories. Accordingly, the narrowly delimited C. verrucosus (Delcourt et al. 1963, 285) has been emended to incorporate the extensive variation referred to.

Uniformly sculptured variants of Tuberositriletes montuosus Döring 1964 are considered to be conspecific with the emended C. verrucosus. However, Döring’s species also incorporates forms with a sculpture that is weakly differentiated (coarser) apically. Its designated holotype (Döring 1964, pl. 4, figs 4–6) appears to be associated with the latter category, but this is uncertain from the illustrations of it.

Concavissimisporites verrucosus is distinguished from C. punctatus (Delcourt & Sprumont) by its coarser sculpture, which is readily discernible in projection at the equator, the equatorial outline of the latter species being essentially smooth. Converrucosisporites pricei McKellar & Cooling sp. nov. is convexly subtriangular to subcircular, and its laesurate margins are less distinctive.

Concavissimisporites penolaensis Dettmann 1963 and C. kutchensis Venkatachala 1969 are difficult to differentiate from C. verrucosus. Lygodium gibberulum Kara-Murza var. minor Kara-Murza 1954 and some of the spores figured by Bolkhovitina [1961, 90, pl. 36, figs 3a, (?)3b, 3c–i, 3k] as L. gibberulum var. gibberula Kara-Murza 1954 are also closely comparable, if not identical with the present species.

Occurrence (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare.

Previous records. Middle Jurassic to Early Cretaceous of Australia (Filatoff 1975; Burger 1976; Helby et al. 1987; Backhouse 1988; Burger 1996; McKellar 1998; Sajjadi and Playford 2002a; Mantle 2009; Mantle and Riding 2012).

Genus Impardecispora Venkatachala, Kar & Raza 1969

(see Supplemental Appendix for type species, synonymy, and other details)

Impardecispora neopunctata McKellar & Cooling sp. nov.

Plate 1, figs 29, 30; Plate 2, figs 1–4; Supplemental Plate 2, figs 26, 27

Synonymy.

1976 Concavissimisporites sp. A; Burger, 5; pl. 2, fig. 2.

2002a  Impardecispora neopunctata McKellar, ‘in press’*; Sajjadi and Playford, 29; pl. 3, figs 7, 12.

1998 Impardecispora neopunctata McKellar*, 72–72; pl. 6, figs 5–6; pl. 7, figs 1–6.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002a, above); see explanatory note in Introduction].

Diagnosis. Spores radial, trilete. Amb subtriangular, apices broadly rounded, sides straight to concave. Laesurae distinct, straight to weakly sinuous, extending 0.6–0.8 spore radius, occasionally bifurcating at equatorial extremities, enclosed within elevated, equatorially tapering, membranous lips (up to 6 μm high at pole; not always preserved); commonly accompanied by a ‘margo’ (obliquely inclined exine giving rise to lips) which narrows sharply near equatorial extremities of suturae; margins tending to gape, with lips compressed within. Exine 1.5–3.5 μm thick; sculpture apically differentiated (coarser, usually more so on proximal apices), comprising grana and, in some specimens, minor verrucae (<0.5 μm high interapically; <1–3.5 μm apically) with subpolygonal, elongate, irregular and infrequently subcircular bases (<0.5–5.5 μm in maximum diameter interapically; <1–7 μm apically). Sculptural elements rounded in profile, spaced up to 1 μm apart, largely coalescent and subreticulate, rarely aligned (and coarsely developed) along laesurate margins. Interapical surfaces sometimes imperceptibly sculptured, appearing almost scabrate.

Dimensions. Equatorial diameter (33 specimens) 38 (78) 112 μm (McKellar 1998). Equatorial diameter (8 specimens) 30.5 (45) 60 μm (this study).

Holotype. Slide A55/2, N42/2; Q299; Plate 2, Figs 1, 2.

Type locality. GSQ DRD 26, 245.85 m, Westbourne Formation.

Etymology. Named to emphasise the close morphological relationship with Concavissimisporites punctatus (Delcourt & Sprumont) Brenner 1963.

Remarks and comparisons. The species, in generally being finely and indistinctly subreticulate, is morphologically intergradational with apically undifferentiated, but otherwise similarly sculptured spores of C. punctatus. Extreme forms of Impardecispora neopunctata display relatively large, discrete grana-verrucae on their proximal apical surfaces (Plate 2, Fig. 3).

Finely sculptured representatives of Trilobosporites ivanovae Batten (1973 pp.414, 416; pl. 43, figs 15–18; pl. 45, figs 1–8; pl. 46, figs 1, 5–9) resemble I. neopunctata. However, Batten’s species is valvate, although only indistinctly so in some specimens (compare Dörhöfer 1977 pp.26–27).

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Late Jurassic and Early Cretaceous of Queensland (Burger 1976; McKellar 1998; Sajjadi and Playford 2002a).

Neoraistrickia parvibacula McKellar & Cooling sp. nov.

Plate 2, figs 5–10; Supplemental Plate 4, figs 18, 19; Supplemental Plate 5, figs 1–3

Synonymy.

2002a  Neoraistrickia parvibacula McKellar, ‘in press’*; Sajjadi and Playford, 36–37, pl. 5, figs 10–11.

2009 Neoraistrickia parvibacula McKellar, ‘in press’*; Mantle, 28–29, pl. 2, fig. 6.

1998 Neoraistrickia parvibacula McKellar*, 89; pl. 11, figs 3–7.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’; (e.g. Sajjadi and Playford 2002a; Mantle 2009; both listed above); see explanatory note in Introduction].

Diagnosis. Spores radial, trilete. Amb rounded subtriangular with straight to weakly convex sides. Laesurae distinct to indistinct, straight to weakly sinuous, extending between 0.8 spore radius and equator, and enclosed within low, narrow lips (<1–3 μm high). Exine <1–1.5 μm thick, baculate distally and equatorially (infrequently baculate-granulate). Bacula <1–2 μm high; bases discrete and subcircular to elongate and partly coalescent, <1–1.5 μm in maximum diameter, spaced up to 2.5 μm (rarely 4.5 μm) apart; columns ± parallel-sided, ca. 0.5 μm wide; apices flatly truncate and slightly expanded. Proximal surface generally with reduced sculpture (baculate to baculate-granulate).

Dimensions. Equatorial diameter (40 specimens) 23 (35) 43 μm; polar diameter (2 specimens) 31, 35 μm (McKellar 1998). Equatorial diameter (74 specimens) 23 (31.5) 43.5 μm (this study).

Holotype. Slide S8876, N27/0; Q345; Plate 2, Figs 6, 7.

Type locality. GSQ DRD 22, 26.75 m, Walloon Coal Measures.

Etymology. Latin: parvus-a-um, small; băcŭlum-i (n), a stick, staff.

Remarks and comparisons. The shortness of the bacula of the present species distinguishes it from other species of Neoraistrickia. Its subtriangular amb provides differentiation from the circular spores of Baculatisporites comaumensis (Cookson).

Occurrence (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to common.

Previous records. Middle Jurassic to Early Cretaceous of Queensland (McKellar 1998; Sajjadi and Playford 2002a); Middle to Late Jurassic of the Bonaparte Basin (Mantle 2009).

Subinfraturma BACULATI Dybová & Jachowicz 1957

Genus Neoraistrickia Potonié 1956

(see Supplemental Appendix for type species and other details, including Supplemental Table 1 for species comparisons)

Neoraistrickia rugobacula McKellar & Cooling sp. nov.

Plate 2, figs 11–25; Supplemental Plate 3, figs 27, 28; Supplemental Plate 4, figs 1–9

Synonymy.

1974 Neoraistrickia sp. A; McKellar, 10–11; pl. 4, fig. 1.

1975 Neoraistrickia sp. A; Filatoff, 52–53; pl. 7, fig. 5.

2002a  Neoraistrickia rugobacula McKellar, ‘in press’*; Sajjadi and Playford, 37, pl. 5, figs 12–13.

2009 Neoraistrickia rugobacula McKellar, ‘in press’*; Mantle, 29, pl. 2, fig. 7.

1998 Neoraistrickia rugobacula McKellar*, 84–86; pl. 10, figs 4–17.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’; (e.g. Sajjadi and Playford 2002a; Mantle 2009; both listed above); see explanatory note in Introduction].

Diagnosis. Spores radial, trilete. Amb convexly subtriangular to almost subcircular. Laesurae distinct to indistinct, straight to weakly sinuous, extending between 0.7 spore radius and equator; enclosed within low lips, <1–2 μm wide. Equatorial exine non-tricrassate to distinctly tricrassate; crassitudes 1.5–3.5 μm wide interradially, narrowing to <1–1.5 μm radially. Distal surface usually sculptured with irregularly distributed, infrequently bifurcating rugulae, 1.5–3.5 μm high, 1.5–3 μm in basal width; crests rounded to acutely subangular or narrow and flange-like in profile, sometimes bearing conate-baculate projections (<1–3 μm high, <1–2 μm in basal diameter). Associated sculpture comprises bacula and less commonly occurring coni, spinulae and verrucae; 1.5–4.5 μm high, with expanded, subcircular to slightly elongate bases, <1–4.5 μm in maximum diameter. Sculptural elements discrete (usually <3.5 μm apart) to coalescent and poorly subreticulate-reticulate in rare specimens. Proximal surface laevigate to indistinctly sculptured with low, broad, radially orientated rugulae, or bearing a continuation of the distal sculpture predominantly in equatorial regions.

Dimensions. Equatorial diameter (86 specimens) 29 (38) 47 μm (McKellar 1998). Equatorial diameter (52 specimens) 23 (30.5) 40.5 μm. (this study).

Holotype. Slide S8807, U37/0; Q332; Plate 2, Figs 11–13.

Type locality. GSQ DRD 22, 104.49 m, Walloon Coal Measures.

Etymology. After the principal sculptural components of the species (rugulae and bacula).

Remarks and comparisons.Neoraistrickia rugobacula encompasses a large group of spores that display extensive morphologic variation intermediate between N. walloonensis and Camarozonosporites ramosus. The occurrence of rugulae is used to distinguish the species from N. walloonensis, and the pronounced development of non-rugulate sculptural projections (bacula, etc.) in extreme subreticulate-reticulate representatives provides differentiation from C. ramosus. However, N. rugobacula normally lacks the development of a subreticulum-reticulum and possesses only a limited number of discrete rugulae distally.

Sajjadi and Playford (2002a, 37) removed Neoraistrickia sp. A McKellar 1974 from synonymy with this species because the former embraced spores with a non-tricrassate exine, unlipped laesurae, and a more uniform sculpture. However, based on the far greater number of specimens seen in this study (52 specimens as opposed to the three specimens observed by Sajjadi and Playford), there is a gradation between tricrassate and non-tricrassate specimens, as well as variability in how uniformly distributed the sculptural elements are on different specimens. Additionally, the presence or absence of lips appears to be a result of preservational effects rather than a defining feature. Based on this, Neoraistrickia sp. A McKellar 1974 is retained in the synonymy of N. rugobacula.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Late Early to Late Jurassic of Queensland (McKellar 1974; McKellar 1998; Sajjadi and Playford 2002a); Middle to Late Jurassic of Western Australia (Filatoff 1975; Mantle 2009).

Neoraistrickia walloonensis (de Jersey) McKellar & Cooling comb. nov.

Plate 2, figs 26–33; Supplemental Plate 4, figs 15–17

Synonymy.

1959 Verrucosisporites walloonensis de Jersey, 356–357; pl. 2, fig. 8 (holotype).

1960 Verrucosisporites walloonensis de Jersey, 5–6; pl. 2, fig. 8 (holotype).

1966 Verrucosisporites walloonensis de Jersey 1959; Hill et al. p. j18; pl. J.9, figs 10–11 (fig. 11: refigured holotype).

1969 Neoraistrickia elongata Reiser & Williams, 4–5; pl. 2, figs 1–3.

1974 Neoraistrickia elongata Reiser & Williams; McKellar, 9; pl. 3, figs 7–11.

2002a  Neoraistrickia elongata Reiser & Williams; Sajjadi and Playford, 35–36; pl. 5, figs 1–3, 6.

1998 Neoraistrickia walloonensis (de Jersey) McKellar*, 83–84; pl. 9, figs 13–17; pl. 10, figs 1–3.

*New combination: Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated but unpublished Geological Survey of Queensland manuscript (McKellar, in press; see explanatory note in Introduction); and cited invalidly (because of the said non-publication) by Sajjadi and Playford (2002a) as Neoraistrickia walloonensis (auct. non de Jersey) in disagreement with McKellar’s (‘in press’) placement of walloonensis as senior to elongata in synonymy (see remarks below).

Description. Trilete spores. Amb subtriangular with straight to convex sides and rounded apices. Laesurae distinct, straight to weakly sinuous, length 0.7 spore radius to approximating the equator, with narrow, equatorially tapering membranous lips. Equatorial exine non-tricrassate to distinctly tricrassate; crassitudes 1–2.5 µm interradially, narrowing to <0.5–1.5 µm radially. Sculptured distally and equatorially with bacula (1–3 µm high, 0.5–2 µm wide) upon discrete to coalescent bulbous bases (up to 4 µm apart, 1–6 µm diameter and 0.5–3.5 µm high). Proximal face with reduced sculpture of finer bacula, grana and occasional low radial ridges.

Dimensions. Equatorial diameter (76 specimens) 19 (28.5) 40 μm. Polar diameter (1 specimen) 28 μm.

Remarks and comparisons.Neoraistrickia walloonensis (de Jersey), following detailed microscopic examination of its poorly preserved and thus very poorly figured holotype (see synonymy above), and N. elongata Reiser & Williams are considered to be conspecific (also the opinion of N.J. de Jersey, personal examination and communication 1990, 1998; compare Sajjadi and Playford 2002a, 35–36). De Jersey (1959, 356–357; 1960b, 5–6) described the sculpture of walloonensis as comprising ‘rounded sub-hemispherical to bluntly conical projections’. These projections essentially conform with the quite variable baculate to tuberculate sculptural elements, generally with squarely-truncate/flatly-truncate apices, described in Neoraistrickia elongata by Reiser and Williams (1969) and McKellar (1974). Further, they are borne on rounded, expanded bases, which appear verruca-like in plan view, especially with poor preservation, and sometimes almost conate in profile [e.g. referring to the synonymy above, see the sculptural elements on distal surface of specimens figured by Reiser and Williams (1969, pl. 2, fig. 2) and McKellar (1974, pl. 3, fig. 10) as N. elongata; and on the equatorial surface of the specimen figured by Playford and Cornelius (1967 pl. 1, fig. 19) as Foraminisporis tribulosus Playford & Dettmann; the latter specimen also indistinctly displays at least some bacula borne on expanded bases on its distal(?) surface].

Hence, a fairly broad concept of N. walloonensis is necessitated, as the species (delimited by the synonymy above) forms part of an extremely broad spore complex that, overall, embraces a very extensive range of continuous morphologic variation (discussed below). Verrucosisporites triangularis de Jersey may be an additional synonym, but its holotype (de Jersey 1959, 357, pl. 2, fig. 9), which was also inspected microscopically, is too inadequately preserved and fragmentary to be certain.

Although the equatorial exine of some representatives of N. walloonensis is more or less uniform in thickness (e.g. de Jersey’s holotype), the majority of spores assigned to the species are weakly tricrassate (compare McKellar 1974; for N. elongata). Proximally, on rare specimens, incipiently-developed, low, broad, radially directed muri are present. Distally, sculptural projections may coalesce basally. However, where distinct muri are developed, the spores are assigned to N. rugobacula McKellar & Cooling sp. nov., which thus grades morphologically into the present species. Neoraistrickia walloonensis is also gradational into N. suratensis McKellar 1974, with fining of sculpture and wall thickness (see below) and Leptolepidites verrucatus Couper 1953, with progressive enlargement of the projection bases and a corresponding decrease in the size, leading to the absence, of the projections borne on them (e.g. Plate 2, fig. 28).

Neoraistricka truncata (Cookson) is distinguished from N. walloonensis by its stoutly truncate bacula and its equatorial exine of uniform thickness [as per the description of Dettmann (1963, 36)]. These species otherwise closely resemble each other, although the latter displays a considerably greater range of morphological variation. Spores assigned to Neoraistrickia sp. A (below) feature a distal reticulum of low, broad muri linking the bacula, which, in equatorial view, can produce a similar appearance to N. walloonensis.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Jurassic to Early Cretaceous of Queensland (de Jersey 1959; Hill et al. 1966; Reiser and Williams 1969; de Jersey 1971a; McKellar 1974; McKellar 1978a; McKellar 1978b; McKellar 1979; McKellar 1981a; McKellar 1985; Burger 1989; McKellar 1998; Sajjadi and Playford 2002a); Jurassic of Western Australia (Filatoff 1975; Burger 1996).

Infraturma MURORNATI R. Potonié & Kremp 1956

Genus Dictyotosporites Cookson & Dettmann 1958

(see Supplemental Appendix for type species and other details)

Dictyotosporites esterleae Cooling sp. nov.

Plate 3, figs 6–19; Supplemental Plate 6, figs 1–11, 17–19

Diagnosis. Trilete spores. Amb subtriangular to subcircular with straight to convex sides and broadly rounded apices. Laesurae distinct to indistinct, straight, 0.5–0.9 spore radius (excluding sculpture) in length, sometimes with narrow, equatorially tapering lips (≤1 μm wide). Laesurae in surface reticulum rarely preserved, indistinct, extending between 0.75 spore radius and periphery. Exine 0.5–2 μm thick; comprehensively sculptured with spinae and bacula (0.5–2 μm wide, 2–5 μm high) with expanded bases (1–3 μm wide) that coalesce forming the rugulae and muri of an inner-reticulum or subreticulum. Inner-reticulum indistinct to distinct with low muri (≤1.5 μm high) that enclose polygonal to circular or irregular lumina 0.5–5.5 μm in maximum diameter. Apical terminations of spinae and bacula thicken and bifurcate, interconnect and anastomose to form a completely enveloping, dense surface-reticulum, with lumina polygonal to elongate-ellipsoidal or irregular, 0.5–7 μm in maximum diameter.

Dimensions. Total equatorial diameter including sculpture: (41 specimens) 24.5 (36.5) 49.5 μm.

Holotype. Slide S16724 K, GSQ DRD 26, 103'5", FHC 1.65 sg (2), X51/0; Plate 3, figs 6–10.

Etymology. JJC: Named after Professor Joan Esterle, one of my two PhD supervisors, the one not already honoured by a taxonomic name!

Type locality. GSQ DRD 26, 31.5 m, Orallo Formation.

Remarks and comparisons.Dictyotosporites esterleae is an important species due to its close superficial resemblance to the palynostratigraphic index species, D. speciosus Cookson & Dettmann 1958. Like the latter, D. esterleae has two superimposed reticula. Moreover, the lumina of the surface-reticula of the two species have overlapping size ranges: 0.5–7 µm for D. esterleae and 1–3 µm for D. speciosus. This overlap makes their differentiation at lower magnifications difficult. The two species are best distinguished by comparing the size of the lumina of the inner-reticulum and the surface-reticula. Dictyotosporites speciosus has a coarser inner-reticulum with notably larger lumina (5–10 µm in diameter) when compared to the lumina of the surface-reticulum. Dictyotosporites esterleae, however, has an inner-reticulum with lumina roughly equal in diameter to those of the surface-reticulum.

Dictyotosporites complex, D. obscurus and D. sandrana all have a surface-reticulum but no inner-reticulum, and D. rugulatus, while also possessing an inner-reticulum, has a much finer surface-reticulum.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare, only occurs in very top of the Westbourne Formation and is sporadic in the Gubberamunda Sandstone, more consistent in occurrence in the Orallo Formation and Mooga Sandstone.

Dictyotosporites obscurus McKellar & Cooling sp. nov.

Plate 4, figs 4–9; Supplemental Plate 5, figs 23–25

Synonymy.

1963 Velosporites triquetrus (auct. non Lantz) Dettmann, 82–83; pl. 19, figs 1–3.

1978 Velosporites triquetrus (auct. non Lantz) Dettmann; Backhouse, 31; pl. 4. Fig. 4.

1980 Velosporites triquetrus (auct. non Lantz) Dettmann; Burger, 61; pl. 15, figs 10, 16.

1988 Retispora triquetra (auct. non Lantz) Backhouse, 67; pl. 9, figs 7a–b; pl. 15, fig. 4.

2002b  Velosporites sp. A; Sajjadi & Playford, 114; pl. 2, fig. 14.

1998 Dictyotosporites obscurus McKellar*, 94–96; pl. 12, figs 19–20; pl. 13, fig. 1.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript, cited by Sajjadi and Playford (2002b, 114), in relation to their Velosporites sp. A (see synonymy above and remarks below), as McKellar (‘in press’; see explanatory note in Introduction).

Diagnosis. Spores radial, trilete. Amb convexly subtriangular, subcircular to slightly irregular. Exine <1–1.5 μm thick, bearing apiculate-spinulate to capillate projections <1–10.5 μm high, with expanded bases <1–1.5 μm in diameter. Rarely detectable unbroken capilli (expanded at both terminations) connect to and support the enveloping, very finely reticulate (punctate-reticulate), sculptural surface; lumina subcircular to slightly elongate, <1 μm (generally <0.5 μm) in diameter, <0.5–2 μm apart. Laesurae in surface reticulum distinct to indistinct, straight to sinuous, extending to periphery, enclosed within membranous, elevated lips with maximum height (up to 4 μm) at pole; laesurae on spore wall, rarely discernible, length up to 0.8 radius (excluding sculpture).

Dimensions. Equatorial diameter (25 specimens) 41 (49) 67 μm; excluding sculpture (projections + reticulum) 30 (37) 43 μm (McKellar 1998). Total equatorial diameter (29 specimens): 37.5 (49) 70 µm; equatorial diameter excluding sculpture (29 specimens): 22.5 (35.5) 49 µm (this study).

Holotype. Slide A80/3, F50/1; Q358; Plate 4, Fig. 4.

Type locality. GSQ DRD 26, 19.02 m, Mooga Sandstone.

Etymology. Latin: obscurus-a-um, obscure, indistinct, unknown, hidden; referring to the structural/sculptural relationship between the spore wall and enveloping reticulate surface.

Remarks and comparisons. The morphography of Australian spores previously assigned to Velosporites triquetrus (Lantz), a species here considered distinct and synonymous with Callialasporites turbatus (Balme), is more complex than hitherto ascertained (compare Dettmann 1963, 82–83). The outer reticulate surface is not loosely enveloping, but connected to, and supported by, projections emanating from the spore wall. Generally, in individual specimens, only a few of these ‘layer’-connecting elements remain intact, the majority (possibly with compression) being broken and reduced to their basal sections (echini of Dettmann 1963) on the exinal surface. Accordingly, D. obscurus sp. nov. has been instituted to accommodate these morphologically deceptive spores.

Individuals embraced by this species are pragmatically indistinguishable from spores recovered from the Upper Jurassic of the Eromanga Basin (Queensland) and described as Velosporites sp. A by Sajjadi and Playford (2002b, 114, pl. 2, fig. 14). Even though these authors did not observe any supporting or interconnecting capilli in their specimens of Velosporites sp. A, there appears to be little doubt that D. obscurus and Sajjadi and Playford’s Velosporites sp. A are conspecific.

In this study, the interconnecting capilli of Dictyotosporites obscurus and the closely related species, D. rugulatus (Sajjadi & Playford) Cooling & McKellar comb. nov., were only rarely visible at the highest magnification (×100 objective lens), with the assistance of filters, and remained essentially elusive from capture by photography.

While these more elusive capilli of Dictyotosporites obscurus and D. rugulatus are a distinguishing feature between these two species and D. complex, the latter species is more readily distinguished based on comparison of surface reticulums. The proportionally larger and frequently subpolygonal to polygonal lumina of Dictyotosporites complex result in a surface reticulum with a more open, ‘lacey’ appearance compared to the denser-appearing surface reticulum of D. obscurus and D. rugulatus. The latter species is distinguished from the former which possesses a distinct inner-reticulum.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare.

Previous records. Late Jurassic to Cenomanian of Australia (Dettmann 1963; Backhouse 1978; Burger and Senior 1979; Burger 1980; Morgan 1980; Dettmann 1986; Backhouse 1988; Burger 1989; McKellar 1998; Sajjadi and Playford 2002b).

Dictyotosporites rugulatus (Sajjadi & Playford) McKellar & Cooling comb. nov.

Plate 3, fig. 20; Plate 4, figs 1–3; Supplemental Plate 5, figs 26–29

Synonymy.

2002b  Velosporites rugulatus Sajjadi & Playford, 113–114; pl. 2, figs 11–13.

1998 Dictyotosporites sp. B. cf. D. obscurus McKellar*, 97; pl. 12, figs 4–7.

*Compared by McKellar (1998) with Dictyotosporites obscurus McKellar sp. nov. (unpublished PhD thesis), then with Sajjadi and Playford (2002b, 113) comparing McKellar’s Dictyotosporites sp. B. cf. D. obscurus McKellar (in deferring to his associated unpublished ‘in press’ manuscript; see explanatory note in Introduction) with their new species, Velosporites rugulatus, considered by them to be distinct, but here regarded as being conspecific.

Description. Trilete spores. Amb circular to broadly subtriangular. Laesurae in spore wall indistinct to distinct, straight to sinuous 0.7–0.9 spore radius (excluding sculpture) in length. Laesurae in surface reticulum rarely preserved, indistinct to distinct, extending to periphery. Exine <1–1.5 µm thick; comprehensively sculptured with fine, rarely perceptible capilli (3–9.5 µm high, expanded bases <1–2.5 µm wide). Expanded bases coalesce forming the rugulae and muri of an inner-reticulum or subreticulum. Inner-reticulum muri are low and rounded (<0.5–1.5 µm high, <1–2.5 µm wide) and enclose subpolygonal to elongate-ellipsoidal lumina or channels (0.5–2.5 µm maximum diameter/width). Apical terminations of capilli bifurcate, interconnect and anastomose forming a completely enveloping, dense surface-reticulum. Surface-reticulum lumina polygonal to circular, <0.5–1.5 µm (rarely ≥1 µm) in diameter, 0.5–2 µm apart.

Dimensions. Total equatorial diameter (30 specimens): 27 (49) 67 μm. Equatorial diameter excluding sculpture (30 specimens): 21 (36) 43 µm.

Remarks and comparisons. The spores identified as Dictyotosporites sp. B. cf. D. obscurus McKellar (1998) and those identified as Velosporites rugulatus Sajjadi & Playford 2002b (pp. 113–114) are undoubtedly conspecific. While Sajjadi and Playford did not observe any of the interconnecting capilli that would have permitted their assignment of this species to Dictyotosporites rather than Velosporites, examination of torn specimens from this study has clearly suggested that some of Sajjadi and Playford’s ‘equatorial coni’ are almost certainly broken capilli. SEM imaging of well-preserved specimens would likely establish this view and assist to firmly settle the generic affiliation of this species and its morphographic relationship with D. obscurus.

Based on observations in this study, while there are some intermediate forms, the spores of D. rugulatus and D. obscurus are readily distinguished respectively by the presence or absence of the low, reticulating muri on the lower surface of D. rugulatus, forming two distinct populations.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare.

Previous records. Late Jurassic and Early Cretaceous of Queensland (McKellar 1998; Sajjadi and Playford 2002b).

Dictyotosporites sandrana McKellar sp. nov.

Plate 4, figs 10–18; Supplemental Plate 6, figs 12–15

Synonymy.

1975 Dictyotosporites pseudophyllanthus (auct. non Tralau) Filatoff, 55, pl. 18, fig. 13, (?)fig14.

1998 Dictyotosporites sandrana McKellar*, 97–98; pl. 13, figs 8–13.

*New species: Validated in publication here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Diagnosis. Spores radial, trilete. Amb subtriangular, with straight to convex sides, to subcircular. Laesurae distinct to indistinct, straight to weakly sinuous, extending between 0.6 spore radius and equator and usually enclosed within narrow, elevated lips (up to 5 μm high). Exine 1–1.5 μm thick, sculptured with a surface subreticulum/reticulum composed of the terminal branches of, and supported on, bacula-like columns (<1–2 μm wide at their weakly expanded bases, 1–5 μm high, spaced up to 6.5 μm apart) of which the termini bifurcate and anastomose to form muri (<1–1.5 μm wide) that enclose polygonal, subcircular, elongate to irregular lumina (1–10.5 μm in maximum diameter). Proximal sculpture confined to equatorial-subequatorial areas or comprehensively developed and reducing in height towards laesurae. This proximal sculpture can be either supported above spore surface, as it is distally and equatorially, or borne directly on it (muri <1–1.5 μm high); points of intersection and terminations of mural elements adjacent laesurae sometimes conspicuously thickened.

Dimensions. Equatorial diameter (24 specimens) 28 (39) 50 μm; excluding sculpture (projections + reticulum) 23 (35) 44 μm (McKellar 1998). Equatorial diameter excluding sculpture (39 specimens) 21 (30.5) 41 µm (this study).

Holotype. Slide S8803, H28/1; Q363; Plate 4, figs 10–12.

Type locality. GSQ DRD 22, 119.61 m, Walloon Coal Measures (McKellar, 1998).

Etymology. JLMcK: After my wife, Sandra (Sandy) Norma McKellar OAM, RN, BN, MN(Res), Dip. M’ment, in great appreciation of her support for an absent and time-consumed husband and father during my prolonged PhD years, especially with three young children to deal with, also likewise recognised as new species herein: Maculatasporites fionabethiana, Retitriletes siobhaniae and Perotrilites cameronii.

Remarks and comparisons. Filatoff (1975; see synonymy above) recorded similar specimens from the Perth Basin as Dictyotosporites pseudophyllanthus (Tralau), and one of his figured specimens (Filatoff’s pl. 18, fig. 13), with image magnification, shows surface projections with weakly expanded bases (as per the diagnosis above). However, it is uncertain that the reticulum of Tralau’s species, originally recorded as Lycopodiumsporites pseudophyllanthus Tralau (1968b, 49–50, pl. 1, figs 6–7), from the Middle Jurassic of Sweden, has the construction of Dictyotosporites Cookson & Dettmann.

Dictyotosporites sandrana is readily differentiated from other species of Dictyotosporites recorded here by its coarser reticulum, which superficially resembles that of spores encompassed by Retitriletes van der Hammen ex Pierce emend. Döring et al. 1963. The latter genus, however, embraces species in which the mural elements of the surface reticulum arise from the spore surface throughout their extent.

Close comparison can be made between the present species and Kekryphalospora distincta Fenton & Riding (1987, 427–434), but the latter, and the associated genus that it represents as type species, were described as having a two-layered exine that is camerate in construction. The cavity between the spore body and the exoexinal reticulum was interpreted as a camera, there being no interconnection observed between the spore body and the reticulum, either equatorially or distally. However, in D. sandrana, the interconnecting elements are commonly broken, and the reticulum may be connected to them only in part on the equatorial and distal surfaces, this making the two species difficult to distinguish. Bases of the broken supporting elements remain on the latter surfaces and give the appearance of widely spaced, verrucate-baculate sculpture. It is further noted that K. distincta has been reported recently from the lower Plover Formation in the Timor Sea, off-shore northwestern Australia, by Riding and Helby (2001). There, it appears at the same stratigraphic level (Toarcian) as D. sandrana in the Surat Basin, all of this advancing the view that the two species are synonymous, and, accordingly, if this is the case, that the exinal construction and morphology of K. distincta, and therefore Kekryphalospora Fenton & Riding, has been incompletely/incorrectly determined. Such a scenario would be comparable to that embraced by comprehension of the construction of D. obscurus sp. nov. (above), circumscribing Australian spores previously assigned to Velosporites triquetrus (Lantz) Dettmann 1963. However, until the type material of K. distincta has been fully reassessed, the two species, K. distincta and D. sandrana, and, for that matter, Dictyotosporites Cookson & Dettmann and Kekryphalospora Fenton & Riding, are here regarded as being distinct.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare.

Previous records. Jurassic of Perth Basin (Filatoff 1975); Surat Basin records of McKellar (1998, 97, Appendices 3–7) embrace the upper Evergreen Formation, Hutton Sandstone, Walloon Coal Measures and Westbourne Formation (late Early Jurassic/Toarcian – Late Jurassic; see Figure 1, this study, for the stratigraphy).

Genus Convolutispora Hoffmeister, Staplin & Malloy 1955

Type.Convolutispora florida Hoffmeister, Staplin & Malloy 1955; original designation.

Remarks and comparisons.Convolutispora Hoffmeister, Staplin & Malloy 1955 is characterised by a circular to subcircular amb and a comprehensive sculpture of closely packed, anastomosing muri separated by narrow, irregular channels and lumina. Sellaspora van der Eem 1983 has generally has coarser sculptural elements.

Affinity. Polypodiophyta (Balme 1995).

Convolutispora prisca McKellar & Cooling sp. nov.

Plate 5, figs 4–6; Supplemental Plate 5, figs 13, 14

Synonymy.

1974 Convolutispora sp. A; McKellar, 11–12; pl. 4, figs 11–12.

2002a  Convolutispora prisca McKellar, ‘in press’*; Sajjadi & Playford, 40–41; pl. 6, figs 16–17.

1998 Sellaspora prisca McKellar*, 118–119; pl. 16, figs 16–17; pl. 17, figs 5–6.

*New species: Validly published here. Originally proposed (as Sellaspora prisca) in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished manuscript (see explanatory note in Introduction), the species being cited by Sajjadi and Playford (2002a) in their synonymy as ‘in press Sellaspora prisca McKellar’. Sajjadi and Playford’s recombination of the (unpublished) species with Convolutispora Hoffmeister, Staplin and Malloy 1955 is supported here by one of us (JJC).

Diagnosis. Spores radial, trilete. Amb subcircular, occasionally oval or rounded triangular, with convex to straight sides; asymmetric proximal-distal compressions common. Laesurae indistinct, straight, extending 0.6–0.7 spore radius; weakly elevated commissures rarely evident. Exine 1.5–3 μm thick, subreticulate to irregularly reticulate; muri usually variable, infrequently uniform in width (<1–4 μm wide), sometimes grading into large, irregular areas of uniformly thickened exine up to 5.5 μm across; lumina narrow, ramifying, channel-like or, where enclosed, equidimensional, elongate or irregular in outline, <1–7 μm in maximum diameter. Subordinate verrucae and grana occur infrequently; bases discrete or partly coalescent with adjacent sculpture, ±equidimensional to elongate in outline, 1.5–7.5 μm in maximum dimeter. Sculptural elements low (<1–rarely 2 μm high), broadly rounded to almost flat in profile. Proximal sculpture sometimes laterally coalescent along laesurate margins. Sparsely distributed, fine grana (minute apiculae in one specimen) usually present in lumina and on sculptural elevations.

Dimensions. Equatorial diameter (41 specimens) 34 (51) 77 μm (McKellar 1998). Equatorial diameter (20 specimens) 23.5 (50) 93.5 μm (this study).

Holotype. Slide S8983, K36/1; Q416; Plate 5, fig. 6.

Type locality. GSQ DRD 23, 107.82 m, Walloon Coal Measures.

Etymology. Latin: priscus-a-um, primitive, ancient.

Remarks and comparisons. In the lower part of its range, this species is a relatively distinct morphographic entity, resembling only verrucate-rugulate and possibly allied spores of Rubinella major (Couper) Norris. However, at slightly higher stratigraphic levels, the species is morphologically intergradational with reticulate representatives of Sellaspora asperata (Dettmann) McKellar & Cooling comb. nov. et emend. The latter are differentiated by higher, coarser muri with expanded crests. Sajjadi and Playford (2002a; see synonymy and attendant footnote above) ‘recombined’ Sellaspora prisca McKellar sp. nov. (unpublished) with Convolutispora Hoffmeister, Staplin & Malloy 1955, maintaining that the species’ sculpture is more compatible with that genus than with Sellaspora.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sometimes sporadic.

Previous records. Late Jurassic of Queensland (McKellar 1998; Sajjadi and Playford 2002a).

Genus Curvaturaspora McKellar & Cooling gen. nov.

Synonymy.

1998 Curvaturaspora McKellar*, 90.

*New genus: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Type.Curvaturaspora frankonense (Achilles) comb. nov.; here designated.

Diagnosis. Spores radial, trilete. Amb subtriangular. Laesurae associated with a well-delimited subequatorial murus, which forms curvaturae. Exine thin, rugulate-reticulate; contact faces laevigate or finely sculptured.

Etymology. Named after the development of curvaturae.

Remarks and comparisons.Lycopodiacidites Couper 1953, to which the type species was originally assigned, lacks the proximal features of Curvaturaspora gen. nov. Moreover, Couper’s genus, according to Raine (1984, 34), is probably synonymous with Retitriletes van der Hammen ex Pierce, as it is distally reticulate (compare Couper 1953, 26).

Affinity. Uncertain (Lycopodialean?).

Curvaturaspora frankonense (Achilles) McKellar & Cooling comb. nov.

Plate 2, figs 34, 35; Plate 3, figs 1–5; Supplemental Plate 7, figs 8–14

Synonymy.

1974 aff. Rugulatisporites sp.; McKellar, 16–16; pl. 5, figs 16–17.

1975 Lycopodiacidites cerniidites (auct. non Ross) Brenner 1963; Filatoff, 47; pl. 4, figs 9a–b, 10.

1981 Lycopodiacidites frankonense Achilles, 34; pl. 7, figs 13–14.

1998 Curvaturaspora frankonense (Achilles) McKellar*, 90–91; pl. 11, figs 8–12.

*New combination: Validly proposed here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Description (updated, after McKellar1998 ). Spores radial, trilete. Amb subtriangular with rounded angles and straight to weakly convex sides. Exine < l–1.5 µm thick, irregularly reticulate distally. Sculpture extends onto proximal surface and coalesces with a subequatorial murus situated 0.6–0.8 spore radius from pole and + parallel to equator. Muri (including subequatorial murus) 0.5–1.5 µm in height and width, spaced up to 3.5 µm apart, sometimes assuming a radial orientation adjacent to subequatorial murus; lumina (where enclosed) equidimensional to elongate and commonly irregular in outline, l–6 µm in maximum dimension. Laesurae distinct to indistinct, straight to weakly sinuous, enclosed within low (<l–3.5 µm high) lips, extending to subequatorial murus where curvaturae are formed in association with it. Contact areas generally well-defined, laevigate or bearing an extension of the reticulate sculpture which becomes progressively finer towards the pole.

Dimensions. Equatorial diameter (50 specimens) 23 (31) 41 µm; polar diameter (10 specimens) 18 (27) 36 μm (McKellar 1998). Equatorial diameter (6 specimens): 25 (32) 39.5 μm (this study).

Remarks and comparisons.Curvaturaspora frankonense is distinguished from Lycopodiacidites cerniidites by a thinner exine, which is not tricrassate, as well as by the characteristic proximal sculpture of this genus. The specimens observed in this study were not always well preserved and the most-representative three here figured are partially obscured by other material. The subequatorial murus is clearly visible on the lower proximal face of Plate 3, Figures 4 and 5, and hints of a less well-developed subequatorial murus are also visible in the specimen shown in Plate 2, Figures 34 and 35, but this specimen, in not being symmetrically compressed, does not readily facilitate observation of this generic characteristic. Also noteworthy is the thin, tricrassate exine of the specimen shown in Supplemental Plate 7, Figures. 10 and 11, which has a combination of features of both C. frankonense and L. cerniidites. This specimen and a few other similar forms have been retained here provisionally in C. frankonense, with the view that examination of a greater number of such specimens may permit the attendant establishment of a new species.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Jurassic of Queensland and Western Australia (McKellar 1974, 1979; Filatoff 1975).

Genus Retitriletes van der Hammen ex Pierce emend. Döring, Krutzsch, Mai & Schulz 1963

(see Supplemental Appendix for type species and other details)

Retitriletes facetus (Dettmann) Srivastava emend. Cooling

Plate 4, figs 19–22; Supplemental Plate 7, figs 25–28

Synonymy.

1963 Lycopodiumsporites facetus Dettmann, 47, pl. 7, figs 17–22.

1975 Retitriletes facetus (Dettmann) Srivastava, 58.

Emended diagnosis. Trilete spores. Amb subcircular to convexly triangular. Laesurae indistinct to moderately distinct, straight to slightly sinuous, 0.8–1 spore radius in length, occasionally with membranous lips (≤1 µm high) preserved. Exine two-layered and acavate, with a thin (<1–1.5 µm thick), homogenous inner layer and a spongeous outer layer (1.5–5 µm thick) that is sculptured distally and equatorially with a regular, net-like reticulum. Membranous muri (≤1–1.5 µm wide) arise from the lower part of the spongeous layer and rise at least as high above the surface of this layer (3–11.5 µm in height measured from base of spongeous layer) as the spongeous layer does above the inner layer. Muri enclose polygonal, subpolygonal or irregular lumina (3–12 µm diameter). Proximal reticulum extends from the equator to the laesurae but is generally finer (lumina 1.5–7 µm diameter) and radially orientated.

Dimensions. Equatorial diameter including sculpture (51 specimens): 21.5 (43.5) 72.5 μm.

Remarks and comparisons. While some other species of Retitriletes have sculpture on their muri or in their lumina, R. facetus (Dettmann) Srivastava emend and R. neofacetus McKellar & Cooling sp. nov. (below) are distinct in possessing a two-layered exine with a thin intexine and a thicker, spongeous exoexine that is also comprehensively reticulate. Differentiation between the two species is provided below under R. neofacetus.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon, sometimes sporadic.

Previous records. Middle Jurassic to Early Cretaceous of Australia (Dettmann 1963; Burger 1974; Backhouse 1975; Filatoff 1975; Burger 1980; Morgan 1980; Dettmann 1986; Helby et al. 1987; Backhouse 1988; Burger 1989; Burger 1996; McKellar 1998; Sajjadi and Playford 2002a; Mantle 2009); Cretaceous of New Zealand (Norris 1968; Raine 1984).

Retitriletes neofacetus McKellar & Cooling sp. nov.

Plate 4, figs 23–27; Plate 5, figs 1–3; Supplemental Plate 8, figs 19, 20, 26–28

Synonymy.

1998 Retitriletes neofacetus McKellar*, 112–113; pl. 15, figs 9–14.

2002a  Retitriletes neofacetus McKellar, in press’*; Sajjadi and Playford p. 47, pl. 8, figs 12, 13.

*New species: Validated in publication here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript, cited by Sajjadi and Playford (2002a, above) as McKellar (‘in press’; see explanatory note in Introduction).

Diagnosis. Trilete spores. Amb subcircular to convexly triangular. Laesurae indistinct to moderately distinct, straight, 0.4–0.9 spore radius in length. Exine two layered and acavate, with a thin (<1–1.5 µm thick) homogenous inner layer, often obscured by a dense spongeous outer layer (1.5–5 µm thick) that is sculptured distally and equatorially with a regular, net-like reticulum. Muri (≤2 µm wide) arise from the lower part of the spongeous layer and rise less than the height of this layer above it (1–7 µm in height measured from the base of the spongeous layer). Muri enclose polygonal, subpolygonal and irregular lumina (3–14 µm in diameter). Distal reticulum extends over the equator to the laesurae but is mostly obscured by the relative height of the spongeous layer.

Dimensions. Equatorial diameter (19 specimens) 35 (41) 50 μm (McKellar 1998).

Equatorial diameter including sculpture (21 specimens): 24.5 (42.5) 71 μm (this study).

Holotype. Slide S8800; T22/0; Q397; Plate 4, Figs 24–26.

Type locality. GSQ DRD 22, 184.38 m, Hutton Sandstone.

Etymology. Named to emphasise the similarity with R. facetus Dettmann 1963.

Remarks and comparisons. Spores with a mural height at least twice the height of the spongeous layer (measured from the same point) are here assigned to R. facetus. This accords well with the species as originally described and figured by Dettmann (1963) and subsequently by others. Spores with muri that do not rise as far above the spongeous layer are placed in R. neofacetus.

Several specimens of Retitriletes neofacetus encountered in the present study possess a particularly dense spongeous layer, which, under most transmitted-light conditions, appears nearly opaque. Specimens with a reticulum that does not extend, in height, notably past the spongeous layer can be difficult to identify as reticulate, requiring maximum light for critical observation.

Retitriletes neofacetus first appears stratigraphically lower than R. facetus, though both have their earliest appearances in the upper Hutton Sandstone (Surat Basin).

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Late Jurassic of Queensland (McKellar 1998; Sajjadi and Playford 2002a).

Retitriletes proxiradiatus McKellar & Cooling sp. nov.

Plate 5, figs 7–15; Supplemental Plate 9, figs 1, 2

Synonymy.

2002a  Retitriletes proxiradiatus McKellar, ‘in press’*; Sajjadi & Playford, 49; pl. 9, figs 1–2, 13.

1998 Retitriletes proxiradiatus McKellar*, 102–103; pl. 13, figs 6–12.

*New species: Validated in publication here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript, cited by Sajjadi and Playford (2002a, above) as McKellar (‘in press’; see explanatory note in Introduction).

Diagnosis. Spores radial, trilete. Amb convexly subtriangular to almost subcircular. Laesurae indistinct to moderately distinct, straight to sinuous, extending between 0.7 spore radius and equator; commissures slightly elevated. Exine 1–2 μm thick, reticulate overall; usually also finely and sparsely granulate. Distal and equatorial reticulum regularly developed; muri 1–3 μm high, bases 1–2 μm wide, crests thin and flange-like to narrowly rounded; lumina polygonal (rarely rounded-elongate) in outline, 2–10 μm in maximum diameter; in rare specimens, small baculate-conate projections occur individually on mural crests at points of intersection (and less commonly in lumina). Proximal exine radially subreticulate; muri <1–4.5 μm wide, low, flat, partly enclosing subcircular and rounded-elongate to elliptical lumina <1–8 μm in maximum diameter.

Dimensions. Equatorial diameter (43 specimens) 24 (35) 47 μm (including sculpture) [McKellar 1998]. Equatorial diameter (30 specimens): 20.5 (27.5) 41.5 μm (excluding sculpture) [this study].

Holotype. Slide S8865, Q37/3, Q374; Plate 5, Figs 7, 8.

Type locality. GSQ DRD 22, 134.01 m, Hutton Sandstone.

Etymology. Referring to the proximal, radially subreticulate muri.

Remarks and comparisons. The proximal face of Retitriletes proxiradiatus, with its low and broadly rounded, radially orientated proximal muri, bears a marked resemblance to the proximal faces of species such as Leptolepidites verrucatus and Camarozonosporites ramosus (de Jersey) McKellar 1974. These species are distinguishable by their distal surfaces and are generally more distinctly tricrassate. Camarozonosporites dorsus may represent an intermediate form between C. ramosus and R. proxiradiatus, with its distal sculpture of broadly rounded muri, each with a narrow, flange-like central ridge. Retitriletes douglasii Dettmann 1986 is closely comparable to R. proxiradiatus, but has narrower proximal muri that enclose open, rectilinear lumina and also terminate freely towards the laesurate margins. The incipiently tricrassate character of some specimens of R. Proxiradiatus in the current study is a feature not previously noted by McKellar (1998).

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon, sometimes sporadic.

Previous records. Jurassic of Queensland (McKellar 1998; Sajjadi and Playford 2002a).

Retitriletes siobhaniae McKellar sp. nov.

Plate 5, figs 16–28; Supplemental Plate 9, figs 21–28

Synonymy.

2002a  Retitriletes siobhaniae McKellar, ‘in press’*; Sajjadi and Playford, 51; pl. 10, figs 1, 2.

1998 Retitriletes siobhaniae McKellar*, 107–108; pl. 14, figs 1–9.

*New species: Validated in publication here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript, cited by Sajjadi and Playford (2002a) as McKellar (‘in press’; see explanatory note in Introduction).

Diagnosis. Spores radial, trilete. Amb convexly subtriangular to subcircular. Laesurae distinct to indistinct, straight to weakly sinuous, extending between 0.7 spore radius and equator, with weakly thickened margins and slightly elevated lips (up to 3 μm high). Exine 1.5–2.5 μm thick; irregularly reticulate to subreticulate distally and equatorially. Muri 2–3 μm high; sides straight to concave; crests expanded, flat to broadly rounded (width <1–3 μm; usually variable in individual specimens). Lumina subcircular, elongate, irregular (<1–20 μm in overall maximum diameter); sometimes sparsely and finely granulate. Proximally, each contact area generally sculptured with a small number of low, discrete and/or partly coalescent grana-verrucae and a single branching or non-branching rugula; proximo-equatorial area commonly bearing a limited extension of distal sculpture.

Dimensions. Equatorial diameter (15 specimens) 40 (48) 57 μm (McKellar 1998). Equatorial diameter (28 specimens): 26 (35.5) 54 μm (this study).

Holotype. Slide A65/2, J27/3; Q383; Plate 5, Figs 16, 17.

Type locality. GSQ DRD 26, 181.61 m, Gubberamunda Sandstone.

Etymology. JLMcK: After my second daughter, Kirstin Siobhan McKellar; Siobhan, Gaelic (=Joan/Judith/Julia; pronounced Shu-vawn; with the emphasis on the second syllable, and awn as in dawn/fawn).

Remarks and comparisons.Retitriletes siobhaniae McKellar sp. nov is distinguished from all other species of Retitriletes by muri with expanded crests and by the extremely variable character of its lumina in both size and shape on a single spore. Specimens of R. siobhaniae with a more regular reticulum most closely resemble R. circolumenus and are likely closely related.

In the current study, in contrast to the findings of McKellar (1998), where the species was not reported below the Gubberamunda Sandstone, occurrences of R. siobhaniae are recorded here from the upper part of the underlying Westbourne Formation.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Late Jurassic and earliest Cretaceous of Queensland (McKellar 1998; Sajjadi and Playford 2002a).

Retitriletes thomsonii Cooling sp. nov.

Plate 5, fig. 29; Plate 6, figs 1–9; Supplemental Plate 9, figs 21–28; Supplemental Plate 10, figs 1–2

Synonymy.

1998 Retitriletes sp. A; McKellar, 115–116; pl. 16, figs 3–5.

Diagnosis. Trilete spores. Amb subtriangular to triangular with straight to convex sides and rounded apices. Laesurae distinct, straight to sinuous, 0.75–0.9 spore radius in length with narrow, equatorially tapering lips (up to 5 µm high at pole). Exine 0.5–1.5 µm thick; comprehensively sculptured with a scabrate to low hamulate (<1 µm in height and <3 µm wide) sculpture. Exine distally and equatorially sculptured with a prominent, if delicate, regular, net-like reticulum. Muri 3.5–7.5 µm high and finely membranous. Lumina polygonal-subpolygonal (6.5–17 µm maximum diameter), sometimes with isolated grana and verrucae (1–3 µm wide). Distal reticulum rarely extends onto the proximal face.

Dimensions. Equatorial diameter (32 specimens): 26.5 (36.5) 54 μm.

Holotype. Slide S16720 K GSQ Dalby 1 214.8 m FHC, G52/0; Plate 6, Figs 1, 2.

Etymology. JJC: Named after my grandfather, Jack Thomson, who immensely supported me during this project.

Type locality. GSQ Dalby 1, 214.8 m, Westbourne Formation.

Remarks and comparisons. The comprehensive scabrate-hamulate sculpture covering the spores, in addition to the delicate net-like reticulum, differentiates Retitriletes thomsonii from other species of Retitriletes recorded here. The algal spores of Maculatasporites eurombahensis McKellar & Cooling sp. nov. and M. fionabethiana McKellar sp. nov. also have scabrate to finely rugose-reticulate lumina but are alete.

The delicate, membranous muri of this species are often variably torn away in places.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon, sometimes sporadic.

Previous records. Late Jurassic of the Surat Basin (McKellar 1998).

Retitriletes johniorum Cooling sp. nov.

Plate 6, figs 12, 13, 16–21; Supplemental Plate 10, figs 17–22, 27–28

Diagnosis. Trilete spores. Amb subtriangular with straight to slightly convex sides and rounded apices. Laesurae generally distinct, straight to slightly sinuous, simple, 0.75–0.9 spore radius in length. Exine 0.5–1 µm thick, comprehensively sculptured with irregularly distributed, anastomosing and bifurcating rugulae, sometimes forming an imperfect subreticulum. Rugulae low and broadly rounded in shape (<0.5–1.5 µm high, 0.5–2.5 µm wide, up to 7 µm apart). Exine otherwise laevigate to faintly scabrate.

Dimensions. Equatorial diameter (22 specimens): 26 (36.5) 46.5 µm.

Holotype. Slide S16926 K GSQ Roma 2 342’7” FHC (2), B41/4; Plate 6, Figs 16, 17.

Etymology. JJC: Named in honour of palynologists: Dr John McKellar (one of my PhD supervisors) and Dr John Filatoff.

Type locality. GSQ Roma 2, 99 m, Orallo Formation.

Remarks and comparisons. Of the specimens observed in this study, many are either torn or folded, obscuring details of their structure, possibly due to the thinness of their exine. Ruffordiaspora has more orderly, and generally closer-spaced sets of muri than observed on Rugulatisporites johniorum. Lycopodiacidites Couper 1953 may have a similar sculpture of irregular rugulae, but with either reduced or absent proximal sculpture, in contrast to the comprehensive sculpture of R. johniorum.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Genus Nodosisporites (Deák) Dettmann & Clifford 1992 

Type. Nodosisporites costatus Deák 1964; original designation.

Remarks and comparisons. Following Dettmann and Clifford (1992, 291), Nodosisporites has evenly distributed supramural bacula, verrucae or spinae. The supramural bacula of Appendicisporites are confined to the radial regions, and the muri of the other cicatricose spores are laevigate. This genus has not previously been reported from Australian sedimentary rocks (Dettmann and Clifford 1992), though Backhouse did figure spores of this type as Cicatricosisporites sp. cf. C. hughesii (1988, pl. 3, figs 6, 7). The genus has been recorded from southern high latitudes elsewhere, including Antarctica (Dettmann and Thomson 1987) and South America (Archangelsky and Archangelsky 2010; Narvaez et al. 2013)

Affinity. Schizaeaceae (Dettmann and Clifford 1992).

Nodosisporites sp. cf. N. crenimurus (Srivastava) Davies 1985

Plate 6, figs 10, 11, 14, 15; Supplemental Plate 10, figs 15, 16, 25, 26

Synonymy.

1987 Nodosisporites cf. crenimurus (Srivastava) Davies; Dettmann and Thomson, fig. 3n.

1988 Cicatricosisporites sp. cf. C. hughesii; Backhouse, 55, pl. 3, figs 6, 7.

Description. Trilete spores. Amb triangular with slightly concave to convex sides and rounded apices. Laesurae distinct, straight-slightly sinuous, 0.9–1 spore radius in length; narrow, equatorially-tapering lips up to 3 µm high at pole. Exine 1.5–3 µm thick, sculptured distally with three to five muri running parallel to each side of the spore. Muri 1.5–3.5 µm wide, 4–6 µm high, separated by 3–4 µm; upper portion (2–4 µm high) of mural crests broken into verrucae 1.5–3.5 µm wide. Muri coalesce at the distal pole but remain separated at the apices. Proximal face laevigate.

Dimensions. Equatorial diameter (7 specimens): 39 (46.5) 59 μm.

Remarks and comparisons. The spores here identified as Nodosisporites cf. N. crenimurus (Srivastava) Davies 1985 are only provisionally identified with this species as the few spores observed were asymmetrically compressed, damaged, still joined in tetrads, or a combination of the aforementioned, impeding confident assignment to the species. Despite these preservational issues, they are readily identified with Nodosisporites, based on the characteristic arrangement of their crenulate/baculate muri. Also, the dimensions above should be regarded as approximate, as only a few measurements could be obtained from each specimen.

Spores of this type have previously been reported as Cicatricosisporites sp. cf. C. hughesii from strata of comparable age in Western Australia by Backhouse (1988) and it is also possible that these or similar forms have been recorded as Cicatricosisporites or Ruffordiaspora by other Early Cretaceous workers in Australia. Considering the tetrad figured by Backhouse (1988, pl. 3, fig. 6) and the tetrads observed here, the species may be more prone to remaining in full or partial tetrads than most members of the genus.

Occurrences (Cooling2020 ). Lower Mooga Sandstone; rare.

Previous records. Early Cretaceous of Western Australia (upper Biretisporites eneabbaensis Zone and Balmeiopsis limbatus Zone) (Backhouse 1988); Cretaceous of Antarctica (Dettmann and Thomson 1987).

Genus Sellaspora van der Eem 1983 

Synonymy.

1983 Sellaspora van der Eem, 250–251.

Type. Sellaspora rugoverrucata van der Eem 1983; original designation.

Remarks and comparisons. The species described below are assigned to Sellaspora van der Eem 1983 due to a strong resemblance to the type species. However, this assignment is only provisional, as the original generic diagnosis describes the exine of the interradial areas as ‘thickened, smooth or with reduced ornamentation’ (van der Eem 1983, 250). The here-reported species show no evidence of a particularly thickened interradial exine, but are retained in Sellaspora for lack of a more fitting repository.

Affinity. Polypodiophyta: Incertae sedis (Sajjadi and Playford 2002b).

Sellaspora asperata (Dettmann) McKellar & Cooling comb. nov. et emend.

Plate 7, figs 1–9, 11, 12; Supplemental Plate 10, fig. 24; Supplemental Plate 11, figs 1–6

Synonymy.

1963 Lycopodiacidites asperatus Dettmann, 40; pl. 6, figs 1–3; fig. 41.

2002a  Sellaspora asperata (Dettmann) emend. McKellar, ‘in press’*; Sajjadi and Playford, 53, pl. 11. Figs 7–9. 12–13.

2009 Sellaspora asperata (Dettmann) emend. McKellar, ‘in press’*; Mantle, 31, pl. 3, fig. 4.

1998 Sellaspora asperata (Dettmann) emend. McKellar*, 116–118; pl. 16, figs 6–15.

*Recombination and emendation: Validly effected in publication here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript, cited by Sajjadi and Playford (2002a) and Mantle (2009) as McKellar (‘in press’); see explanatory note in Introduction.

Emended diagnosis. Spores radial, trilete. Amb subcircular, oval or rounded triangular, with convex to almost straight sides; asymmetric proximal-distal compressions common. Laesurae indistinct, straight, extending 0.6–0.8 spore radius. Exine 1.5–3 μm thick. Sculpture comprehensive, extremely variable, usually increasing in height towards equator; in composition: (i) commonly comprising intergradational rugulae, verrucae and subordinate grana (also bacula, coni and rare spinae equatorially); closely spaced and discrete or variably coalescent and non-reticulate to subreticulate; grana-verrucae equidimensional, elongate to irregular in basal outline, 1.5–10.5 μm in maximum diameter; rugulae generally irregular in shape and distribution, <4 μm high, <1–4 μm wide, sometimes grading into large irregular areas of uniformly thickened exine up to 8 μm across; bacula 4–6.5 μm (rarely 9 μm) high, 1.5–6 μm in basal diameter; coni/spinae usually <5 μm in height and basal diameter; or (ii) irregularly reticulate; muri ± uniform to slightly variable in width (<1–2 μm wide), 1.5–3.5 μm high; lumina narrow, ramifying, channel-like or, where enclosed, equidimensional elongate to commonly irregular in outline, <1–9 μm in maximum diameter, usually finely and sparsely granulate. Apices of coni/spinae acutely rounded to pointed; apices/crests of remaining elements irregular (some bacula and verrucae) to commonly flat and expanded, appearing variously smooth, punctate, intrareticulate, scabrate and often finely granulate. Sculptural elements sometimes with closer spacing and greater coalescence along laesurate margins, forming an indefinite margo; distinct in projection at equator.

Dimensions. Equatorial diameter (53 specimens) 34 (54) 72 μm (including sculpture) (McKellar 1998). Equatorial diameter (71 specimens): 24.5 (47) 72 μm (including sculpture) (this study).

Remarks and comparisons. Formal emendation of S. asperata has been undertaken in order to delimit the extremely diverse and continuous variation encountered here and by McKellar (1998). Moreover, the species has been transferred to a new combination with Sellaspora van der Eem because this genus more appropriately encompasses its morphography than Lycopodiacidites Couper (despite the reservations expressed above under the generic heading), as represented by its type species, L. bullerensis Couper. A re-examination of Couper’s species (Raine 1984, 34) has indicated that it is distally reticulate (compare Couper 1953, 26, pl. 1, fig. 9) and may be conspecific with Retitriletes eminulus (Dettmann) Srivastava 1977.

Sellaspora dettmanniae (Burger) comb. nov. is a closely comparable form, but generally displays distinctly finer sculpture. One of the figured specimens of S. asperata (Figs 25F–H) approaches Burger’s species in the small size of its sculptural elements, but is comprehensively subreticulate. Nonetheless, the indication is that the two species are morphologically intergradational. Sellaspora ambifoveolata (Brenner) comb. nov. has reduced proximal sculpture and longer(?) laesurae, but otherwise appears to be indistinguishable from S. asperata.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Middle Jurassic to Early Cretaceous of Australia (Dettmann 1963; Burger 1974; Backhouse 1975; Filatoff 1975; Burger 1976; Burger and Senior 1979; Burger 1980; Burger 1989; Burger 1996; McKellar 1998; Sajjadi and Playford 2002a; Mantle 2009).

Sellaspora passa McKellar & Cooling sp. nov.

Plate 7, figs 10, 13–24; Supplemental Plate 11, figs 7, 8, 26

Synonymy.

2002a  Sellaspora passa McKellar, ‘in press’*; Sajjadi and Playford, 53; pl. 11, figs 14–16.

1998 Sellaspora passa McKellar*, 119–121; pl. 17; figs 7–16.

*New species: Validated in publication here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript, cited by Sajjadi and Playford (2002a) as McKellar (‘in press’; see explanatory note in Introduction).

Diagnosis. Spores radial, trilete. Amb subcircular, sometimes oval or convexly subtriangular; occasionally with slightly asymmetric proximal-distal compression. Laesurae indistinct, straight, extending between 0.6–0.8 spore radius. Exine 1–3 μm thick. Sculpture comprehensive, extremely variable, increasing in height towards, and projecting 2–7 μm beyond, equator; generally comprising intergradational grana, verrucae, rugulae and bacula (rarely coni and spinae); grana–verrucae subcircular, elongate to irregular in basal outline, <1–5 μm in maximum diameter; rugulae irregular in width (<1–3 μm wide); bacula, coni and spinae 1–3 μm in basal diameter. Sculptural elements closely spaced, bases variably coalescent, and non-reticulate to irregularly reticulate; sometimes denser and more coalescent along laesurate margins, forming an indefinite margo. Apices/crests generally expanded, at least partly into broad pila-like or arborescent terminations which coalesce with those of adjacent elements to form an outer ‘fusion zone’; terminal coalescence confined to equatorial area or developed also on proximal and distal surfaces; ‘fusion zone’ densely intrareticulate to ± homogeneous, 1–3 μm thick equatorially (thickness not always determinable), variously appearing scabrate, finely granulate or infrequently laevigate on its external surface.

Dimensions. Equatorial diameter (41 specimens) 46 (63) 89 μm; polar diameter (1 specimen) 53 μm (McKellar 1998). Equatorial diameter including sculpture (22 specimens): 40 (60) 73 μm (this study).

Holotype. Slide S9801, Z39/2; Q418; Plate 7, Figs 13, 14.

Type locality. GSQ DRD 25, 37.99 m, Westbourne Formation.

Etymology. Latin: passus-a-um, outspread; referring to the apical/crestal fusion of sculptural elements.

Remarks and comparisons.Sellaspora passa sp. nov. and S. asperata (Dettmann) comb. nov. et emend. are morphologically intergradational. In Dettmann’s species, however, the apices/crests of the sculptural elements, although commonly expanded, are non-coalescent.

An extremely broad comparison can be made with Tessellatosporis escheri Harding (1988, 165–173, pl. 1–3; Early Cretaceous, England), which possesses a three-layered exospore incorporating regularly spaced columns surmounted by expanded, discrete elements (immature stage) to interdigitating elements (mature stage).

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare.

Previous records. Late Jurassic of Queensland (McKellar 1998; Sajjadi and Playford 2002a).

Sellaspora ambifoveolata (Brenner) McKellar & Cooling comb. nov.

1963 Lycopodiacidites ambifoveolatus Brenner, 63, pl. 17, figs 1–2.

1998 Sellaspora ambifoveolata (Brenner) McKellar*, 122.

*New combination: Validated in publication here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Remarks. Brenner’s species (not recorded in the study material) is combined with Sellaspora van der Eem, consistent with the treatment accorded to the closely allied species, S. asperata (Dettmann) comb. nov. et emend.

Sellaspora dettmanniae (Burger) McKellar & Cooling comb. nov.

1980 Lycopodiacidites dettmanniae Burger, 52, pl. 5, figs 6–8.

1998 Sellaspora dettmanniae (Burger) McKellar*, 122.

*New combination: Validated in publication here. Originally Proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Remarks. As for S. ambifoveolata (above).

Genus Trachysporites Nilsson 1958

Type. Trachysporites fuscus Nilsson 1958; original designation.

Affinity. Polypodiophyta: Incertae sedis (Sajjadi and Playford 2002a).

Trachysporites infirmus (Balme) McKellar & Cooling comb. nov.

Supplemental Plate 11, figs 17, 18

Synonymy.

1957 Concavisporites infirmus Balme, 21; pl. 2, figs 32–33.

1958 Concavisporites subgranulosus Couper, 143; pl. 22, fig. 6.

1969 Granulatisporites sp.; Reiser & Williams, 3; pl. 1, fig. 5.

1970 Concavissimisporites subgranulosus (Couper) Pocock, 41; pl. 7, figs 24, 26.

1974 Granulatisporites sp. A; McKellar, 5–6; pl. 1, figs 12–13.

1975 Granulatisporites sp.; Filatoff, 71; pl. 17, figs 3–4.

1988 Concavissimisporites infirmus (Balme) Backhouse, 55–56; pl. 3, figs 12–14; pl. 12, figs 4–5.

2002a  Trachysporites infirmus (Balme) McKellar, ‘in press’*; Sajjadi and Playford, 56–57; pl. 12, figs 4–5.

2002a  Concavissimisporites subgranulosus (Couper) Pocock; Sajjadi and Playford, 26; pl. 2, figs 14–15.

1998 Trachysporites infirmus (Balme) McKellar*, 122–124; pl. 17, figs 1–4.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002a, above); see explanatory note in Introduction].

Dimensions. Equatorial diameter (51 specimens): 20 (32) 53.5 μm.

Remarks and comparisons. Sajjadi and Playford (2002a) distinguished the current species and Concavissimisporites subgranulosus Couper 1958 from each other on the basis of the presence or absence of a kyrtome (present on T. infirmus) and by the strictly granulate sculpture of C. subgranulosus. However, examination of Couper’s figured material (1958, pl. 22, fig. 6) shows it possess both grana and rugulae. Furthermore, in this study, very few spores of either type possessed a recognisable kyrtome.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon, mostly uncommon.

Previous records. Jurassic and Early Cretaceous of Australia (Balme 1957; Reiser and Williams 1969; McKellar 1974; Filatoff 1975; Backhouse 1988; Burger 1996; McKellar 1998; Sajjadi and Playford 2002a; Mantle 2009; Mantle and Riding 2012). Jurassic and Early Cretaceous of Antarctica (Mohr and Gee 1992; Bomfleur et al. 2014).

Subturma ZONOTRILETES Waltz 1935

Infraturma AURICULATI Schopf emend. Dettmann 1963 

Genus Cibotiidites Ross 1949 

Synonymy.

1947 Trilites Cookson, 136 (nom. nud.).

1949 Cibotiidites Ross, 32.

1953 Trilites Cookson ex Couper, 29.

1963 Cibotiidisporites Danzé-Corsin & Laveine*, 82.

1963 Trilites Cookson ex Couper emend. Dettmann, 61–62.

1974 Cibotiidites Ross; Skarby, 2–3.

For additional synonymy, see Dettmann (1963, 61) and Skarby (1974, 2).

*Obligate junior synonym of Cibotiidites Ross, having the same type species.

Cibotiidites volkheimeri (Filatoff) McKellar & Cooling comb. nov.

Plate 7, figs 25–27; Supplemental Plate 11, figs 24, 25, 28

Synonymy.

1972 Ischyosporites sp. A; Volkheimer, 122–123; pl. 6, figs 52–53.

1972 Ischyosporites sp. B; Volkheimer, 123; pl. 6, fig. 54; pl. 7, fig. 55.

1972 Ischyosporites sp. C; Volkheimer, 123–124; pl. 7, figs 56–57.

1975 Ischyosporites volkheimeri Filatoff, 67–68; pl. 14, figs 9–10.

2002a  Trilites volkheimeri (Filatoff) Sajjadi & Playford, 59; pl. 12, figs 1–3. [non Trilites volkheimerii (sic) Baldoni 1987, 75; pl. 2, figs 1–2].

2003 Trilites wolfgangii Sajjadi & Playford, 171.

2005 Cibotiidites volkheimeri*; Cooper, 94, fig. 9.3.

1998 Cibotiidites volkheimeri (Filatoff) McKellar**, pl. 20, figs 10–15.

*Invalid publication of this binary combination, as no reference to the basionym [Article 41, International Code of Nomenclature for Algae, Fungi, and Plants (Turland et al. 2018)], although based on the basionym, Ischyosporites volkheimeri Filatoff [Ian Raine, personal communication, February, 2013; the compiler of figure 9.3 in Cooper (2004)].

**Recombination validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Dimensions. Equatorial diameter (107 specimens): 24 (36) 73.5 μm; Length of monolete forms (5 specimens): 35 (41.5) 47 μm.

Remarks and comparisons.Ischyosporites volkheimeri Filatoff 1975 was recombined with Trilites Cookson ex Couper emend. Dettmann 1963 by Sajjadi and Playford (2002a, 59–60, pl. 12, figs 1–3). Subsequently, this binomen was found to be preoccupied [Trilites volkheimerii (sic) Baldoni 1987], and, as a consequence, this led to the proposal of a new specific epithet, Trilites wolfgangii Sajjadi & Playford (2003, 171; see synonymy above). However, Trilites Cookson ex Couper has been regarded as a junior synonym of Cibotiidites Ross 1949 (Skarby 1974, 2–3), and this view, upon further consideration (compare McKellar 1998, 136), is supported here. Accordingly, Filatoff’s epithet, volkheimeri, is recombined with Cibotiidites Ross, as it has priority over wolfgangii in this new combination.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to common.

Previous records. Middle Jurassic to Early Cretaceous of Australia (Filatoff 1975; McKellar 1980; McKellar 1998; Sajjadi and Playford 2002a); Middle Jurassic and Early Cretaceous of South America (Volkheimer 1972); Cretaceous of Antarctica (Dettmann and Thomson 1987).

Infraturma TRICRASSATI Dettmann 1963 

Genus Camarozonosporites Pant ex Potonié emend. Klaus 1960

(see Supplemental Appendix for type species and other details)

Camarozonosporites dorsus Cooling & McKellar sp. nov.

Plate 8, figs 1–4; Supplemental Plate 12, figs 25–28

Diagnosis. Trilete spores. Amb subcircular to subtriangular with straight to convex sides and rounded apices. Laesurae variably distinct, simple, 0.8–1 spore radius in length. Exine tricrassate (1–1.5 μm thick; crassitudes 1.5–2 μm thick); sculptured distally and equatorially with a regular reticulum of broadly rounded muri (1.5–3 μm wide, 1–2 μm high) with narrow crests (≤0.5 μm wide, <0.5–1 μm high) running along the centres. Muri enclose subcircular or subpolygonal lumina (3–6 μm maximum diameter). Proximal face bearing a sculpture of radially orientated, broadly rounded muri (1.5–2.5 μm wide, <0.5–2 μm apart).

Dimensions. Equatorial diameter (28 specimens): 22.5 (27.5) 31.5 μm.

Holotype. S16728 K GSQ DRD 26 216'9" (1), W52/2, Plate 8, Figs 1, 2.

Etymology. Latin: dorsus-i (m), back, ridge, ledge, slope of hill; referencing the narrow ridges running along the centres of the muri.

Type locality. GSQ DRD 26, 66 m, Orallo Formation.

Remarks and comparisons. Spores of Camarozonosporites dorsus sp. nov. are here distinguished from those recorded as C. ramosus by the presence of the narrow, centrally located ridges atop their muri. Camarozonosporites dorsus may represent an intermediate form between Camarozonosporites ramosus and Retitriletes proxiradiatus. The latter species has a proximal sculpture akin to that of C. ramosus and a distal sculpture with lumina of similar size (2.5–8 μm maximum diameter) to those of C. dorsus enclosed by narrow muri with sometimes expanded bases (up to 2.5 μm wide).

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Camarozonosporites pudens (Balme) McKellar & Cooling comb. nov.

Plate 8, figs 5, 6; Supplemental Plate 12, figs 5, 6

Synonymy.

1957 Reticulatisporites pudens Balme, 17–18; pl. 1, figs 12–14.

1988 Leptolepidites pudens (Balme) Backhouse, 60–61; pl. 6, fig. 9; pl. 13, figs 9–11.

1998 Camarozonosporites pudens (Balme) McKellar*, 150; pl. 22, fig. 13.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Description. Trilete spores. Amb subcircular to subtriangular with straight to convex sides and rounded apices. Laesurae variably distinct, simple, 0.8–1 spore radius in length. Exine (1–2 μm thick) either undifferentiated or incipiently tricrassate; sculptured distally and equatorially with a regular reticulum of broadly rounded muri (1.5–2 μm high; 1.5–3 μm wide) enclosing circular or elongate-ellipsoidal lumina (1–3.5 μm maximum diameter). Proximal face laevigate or sculptured with radially arranged, low, broad muri (2–3 μm wide, set 0.5–2 μm apart), and rarely with an equatorially tapering kyrtome paralleling the trilete mark (2–3 μm wide).

Dimensions. Equatorial diameter (24 specimens): 26.5 (32.5) 38 μm.

Remarks and comparisons. In spores recorded here, the equatorial exine is variably structured, being either thin and undifferentiated or incipiently to weakly tricrassate. Their proximal exine is laevigate or faintly reticulate to radially subreticulate (also see Backhouse 1988; compare: Balme 1957; Dettmann 1963). A morphologically intergradational relationship with C. ramosus (de Jersey) is thus apparent, hence the generic reassignment. Camarozonosporites pudens, however, is distinguished from de Jersey’s species by its smaller, although overlapping size range and its more densely reticulate distal sculpture. Unlike C. ramosus, it does not include forms that are conspicuously tricrassate.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Late Jurassic to Early Cretaceous of Australia (Balme 1957; Dettmann 1963; Burger and Senior 1979; Burger 1980; Backhouse 1988; Burger 1989; McKellar 1998).

Genus Foveosporites Balme emend. McKellar & Cooling

Synonymy.

1957 Foveosporites Balme, 17.

1963 Sestrosporites Dettmann, 66.

1998 Foveosporites Balme emend. McKellar*, 160–161.

*Emendation: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Type. Foveosporites canalis Balme 1957; original designation.

Emended diagnosis (after McKellar 1998). Spores radial, trilete. Amb rounded subtriangular to subcircular. Laesurae extend between 0.75 spore radius and equator, enclosed within low, narrow lips. Exine incipiently tricrassate to distinctly tricrassate. Sculpture foveolate to foveoreticulate; with/without small projections (bacula, coni, spinae, etc.) on the interfoveolate exine.

Remarks and comparisons. Emendation of the genus has been undertaken to incorporate the development of interradial equatorial crassitudes referred to below in the type species (also see: Backhouse 1988, 58; Burger 1980, 54). Although F. canalis is not invariably tricrassate, it is proposed that Foveosporites be restricted to species which encompass some tricrassate individuals or which at least are incipiently tricrassate. Species completely lacking any tendency towards such equatorial differentiation are excluded. Sestrosporites Dettmann is regarded as a junior synonym. Vallizonosporites Döring is also placed in the synonymy of the emended Foveosporites, as its thin hyaline zona is indistinguishable from the ‘zona’ that develops as a secondary feature in certain species closely allied with F. canalis [F. pseudoalveolatus (Couper) Voronova and Coronatispora perforata Dettmann; see remarks under these species in the Supplemental Appendix.

Coronatispora Dettmann is distinguished from Foveosporites by the development of a distal polar crassitude and circumpolar ridge.

Affinity. Lycopodiophyta (Balme 1957; Balme 1995).

Proposed new combinations.

Foveosporites irregulatus (Couper) McKellar & Cooling comb. nov.

1958 Foveotriletes irregulatus Couper, 143, pl. 22, figs 9–10.

1963 Sestrosporites irregulatus (Couper) Dettmann, 66.

Foveosporites vallifoveatus (Döring) McKellar & Cooling comb. nov.

1965 Vallizonosporites vallifoveatus Döring, 60, pl. 13, figs 1–2.

Foveosporites acutus (Tralau) McKellar & Cooling comb. nov.

1968 Sestrosporites acutus Tralau, 62, pl. 11, fig. 3.

Genus Leptolepidites Couper emend. McKellar & Cooling

Synonymy.

1953 Leptolepidites Couper, 28.

1968 Leptolepidites Couper emend. Norris, 316.

1998 Leptolepidites Couper emend. McKellar*, 151–152.

*Emendation: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, in press; see explanatory note in Introduction).

Type. Leptolepidites verrucatus Couper 1953; original designation.

Emended diagnosis (after McKellar 1998). Spores radial, trilete. Amb rounded subtriangular to subcircular. Laesurae long, simple or with limited lip development. Equatorial exine distinctly to incipiently tricrassate. Distal surface generally verrucate to verrucate-rugulate. Proximal surface laevigate or faintly sculptured.

Remarks and comparisons. The genus has been emended to incorporate the development of interradial equatorial crassitudes, described below in L. verrucatus. As the type species is not invariably tricrassate, it is intended that the genus be restricted to species possessing at least some tricrassate individuals. Species completely lacking any tendency towards such equatorial differentiation are excluded.

Camarozonosporites Pant ex Potonié emend. Klaus 1960 is differentiated by its rugulate distal sculpture. Camarozonotriletes Naumova ex Ishchenko 1952, according to the diagnosis of Potonié (1958, 31; see Jansonius and Hills 1976 cards 370, 372), is laevigate or finely sculptured with grana, small verrucae, or coni. Rubinella Maliavkina ex Maliavkina emend. Potonié 1960 lacks development of interradial equatorial crassitudes.

Uvaesporites Döring, based on the emendation of Helby (in de Jersey 1971b, 5), is distinguished by its layered (often cavate), cingulate exine and sharply delineated contact faces (compare Achilles et al. 1984, 41).

Affinity. Lycopodiophyta (Filatoff 1975).

Genus Annulispora de Jersey 1959 

(see Supplemental Appendix for synonymy, type species, and other details)

Annulispora canalicula (Filatoff) emend. McKellar & Cooling

Plate 8, figs 7–16; Supplemental Plate 13, figs 8, 9

Synonymy.

1975 Rogalskaisporites canaliculus Filatoff (pars), 39; pl. 1, figs 8a–b, 9, (?)fig. 10 (non fig. 7).

2002a  Annulispora canalicula (Filatoff) McKellar, ‘in press’*; Sajjadi and Playford (pars), 68–69; pl. 14, (?)fig. 8 [(?)non fig. 6–7; non text-figs 8a–c].

1998 Annulispora canalicula (Filatoff) emend. McKellar*, 178–179; pl. 26, figs 9–18.

*Emendation: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002a, listed above); see explanatory note in Introduction].

Emended diagnosis (after McKellar 1998). Spores radial, trilete, acingulate to cingulate. Amb convexly subtriangular to subcircular. Laesurae distinct, straight; suturae 0.5–0.8 spore radius (rarely reaching equator); bordered by a low, equatorially tapering margo (2–5.5 μm wide at pole), which may extend beyond suturae to equator. Equatorial exine <1–2 μm thick; usually narrowly and uniformly cingulate. Distal sculpture comprises two concentric circumpolar ridges, the inner situated directly about the pole, and the outer at 0.3–0.4 spore radius therefrom, respectively 2–4.5 μm and 2.5–5.5 μm wide. Radially arranged crassitudes (up to 3.5 μm wide) interconnect the two circumpolar ridges (delimiting an annular zone of small ± equidimensional lumina), and others extend from the outer ridge to, or partly to, the equator (delimiting a second zone of narrow lumina that are elongated radially). Inner circumpolar ridge encloses an equidimensional area (1–7 μm in diameter) with or without a small crassitude (up to 3 μm in diameter) centred on the pole. Proximal exine laevigate or scabrate-granulate (corrosion).

Dimensions. Equatorial diameter (42 specimens) 24 (34) 46 μm (McKellar 1998). Equatorial diameter (23 specimens): 23.5 (33) 42 μm (this study).

Remarks and comparisons.Annulispora canalicula has been restricted here to spores like the holotype (Filatoff 1975, pl. 1, figs 8a–b), which, apart from their radial sculpture, possess a very small, sometimes inconspicuous, polar crassitude enclosed concentrically by two annular ridges. Also included are otherwise identical individuals in which a polar crassitude is absent. Forms with a relatively large (non-annular) polar crassitude enclosed concentrically by (and radially interconnected with) a single circumpolar ridge (e.g. Filatoff 1975, pl. 1, fig. 7) are excluded, being herein included as A. folliculosa. In synonymy, Sajjadi and Playford (2002a; see synonymy above) followed Filatoff’s descriptive concept of the species, but, in their own description and in their Text-figures 8a–c, informally and expressly extended the species to include forms where a polar crassitude is sometimes present and others (their Text-figures 8b–c) where radially arranged crassitudes are absent between the distal circumpolar ridge and the polar crassitude, a morphographic arrangement here more associated with A. folliculosa, although the distal polar crassitude in their Figure 8 may be thinner at its very centre. Such a feature would be representative of a ‘micro-annular’ ridge, and thus that specimen falls, with some intricacy, into the concept espoused here (and by McKellar 1998) for A. canalicula.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Middle and Late Jurassic of Australia (Filatoff 1975; McKellar 1998; Sajjadi and Playford 2002a; Mantle 2009).

Annulispora folliculosa (Rogalska) de Jersey 1959 

Plate 8, figs 17–24; Supplemental Plate 13, figs 4–7

Synonymy.

1954 Sporites folliculosus Rogalska, 26, 38, 44; pl. 12, fig. 8.

1954 Sporites lunaris Rogalska, 26, 38, 45; pl. 12, fig. 9.

1959 Annulispora folliculosa (Rogalska) de Jersey, 358; pl. 2, fig. 2.

1959 Annulispora densata de Jersey, 358–359; pl. 2, figs 3–4.

1975 Rogalskaisporites canaliculus Filatoff (pars) p. 39; pl. 7, fig. 7 only [non pl. 1, figs 8a–b (holotype), 9, (?)10)]

2002a  Annulispora canalicula (Filatoff) McKellar*; Sajjadi and Playford (pars), 68–69; pl. 14, (?)fig. 6, fig. 7 (non fig. 8); text-fig. 8a (non text figs 8b–c).

2002a  Annulispora densata de Jersey; Sajjadi and Playford, 69–70; pl. 14, figs 9–10; text-figs 8d–e.

1998 Annulispora folliculosa (Rogalska) de Jersey; McKellar*, 175–176 pl. 26, figs 2–6.

1998 Annulispora sp. A; McKellar*, 179–180 pl. 26, figs 19–21.

*Cited in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript referred to by Sajjadi and Playford (2002a) as McKellar ‘in press’; see explanatory note in Introduction. In the synonymy above, Annulispora sp. A of McKellar is herein recognised as falling within a more broadly circumscribed A. folliculosa (Rogalska).

Description. Trilete spores, variably cingulate. Circular to subcircular amb. Laesurae distinct, straight to slightly sinuous, 0.5–0.8 spore radius in length; distinct to indistinct, equatorially tapering margo up to 3 μm wide at pole. Cingulate equatorial exine 1–2.5 μm thick; proximal surface laevigate, distal surface variable sculptured. Distal sculpture bears some combination of the following, always including:

  • circumpolar ridge (1.5–6 μm wide) approximately parallel to amb, located ca. 0.5 spore radius from pole

  • laevigate polar crassitude 3.5–7 μm in diameter

  • radial ridges 1.5–6 μm wide, 0.5–3 μm apart, connecting any of the above

  • dispersed, low grana and verrucae <0.5–3 μm in maximum diameter.

Dimensions. Equatorial diameter (79 specimens) 21 (33) 43 µm (McKellar 1998). Equatorial diameter (50 specimens): 26 (31) 44 μm (this study).

Remarks and comparisons.Annulispora folliculosa is broadly interpreted here to encompass not only the range of distal morphography described by McKellar (1974), but also forms referred to by him as Annulispora sp. A (see synonymy above). The latter individuals represent spores excluded also hereunder from A. canalicula, to which they were assigned by Filatoff (1975). As previously interpreted for A. folliculosa (McKellar 1974), they are similarly sculptured distally by a disc-like polar crassitude and a concentrically encircling circumpolar ridge situated approximately midway between the pole and equator. Further, radially disposed crassitudes likewise extend from the ridge’s outer margin towards the equator. However, the additional feature now associated here with A. folliculosa and one that was attributed to the here-excluded variant of A. canalicula by Filatoff (1975: see synonymy) is the occurrence of a second, generally inconspicuous series of radial thickenings which interconnect the polar crassitude with the circumpolar ridge.

The single specimen figured by Backhouse (1988, pl. 10, fig. 6) as Rogalskaisporites canaliculus, from the Perth Basin (Western Australia), may be conformable with this concept. Other specimens, from southeastern Queensland, that are also seemingly conformable include:

  • Annulispora folliculosa (Rogalska); de Jersey 1962, pl. 1, fig. 18 (Late Triassic of the Ipswich Coalfield).

  • Annulispora folliculosa (Rogalska); McKellar 1974, pl. 7, fig. 16; pl. 8, fig. 2 (Jurassic of the Surat Basin).

  • Annulispora densata de Jersey 1959, pl. 2, fig. 3 (holotype), fig. 4 (reprinted 1960: see this reprint for marginally superior photomicrography) [Jurassic of the Clarence-Moreton Basin].

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sometimes sporadic.

Previous records. Late Triassic to Early Cretaceous of Australia (de Jersey 1959; de Jersey 1962; de Jersey 1963; de Jersey 1964; de Jersey and Paten 1964; Playford and Dettmann 1965; Hill et al. 1966; de Jersey and Hamilton 1967; Burger 1968; Reiser and Williams 1969; de Jersey 1971b; de Jersey 1971a; McKellar 1974; Filatoff 1975; McKellar 1975; McKellar 1978a; Burger and Senior 1979; McKellar 1979; Burger 1980; McKellar 1981b; Burger 1989; Burger 1996; McKellar 1998; Backhouse and Balme 2002; Sajjadi and Playford 2002a; Mantle 2009; de Jersey and McKellar 2013).

Genus Antulsporites Archangelsky & Gamerro 1966

Synonymy.

1966a  Heliosporites Archangelsky & Gamerro, 203; non Schulz 1962; non Mortimer & Chaloner 1967.

1966c  Antulsporites Archangelsky & Gamerro, 369.

1967 Verrucingulatisporites Hiltmann, 172; non Kedves 1961.

Type.Antulsporites saevus (Balme) Archangelsky & Gamerro emend. McKellar & Cooling [=Antulsporites baculatus (Archangelsky & Gamerro) Archangelsky & Gamerro 1966]; Type designated by Archangelsky & Gamerro (1966c).

Remarks and comparisons. As Heliosporites Archangelsky & Gamerro was found to be a homonym of Heliosporites Schulz (1962), Archangelsky and Gamerro (1966c) proposed the name Antulsporites in its place. However, their nominated type species (A. baculatus) is regarded here as a junior synonym of A. saevus (recorded below).

The genus encompasses spores with a radially structured (ribbed, striated, incised) cingulum and an exine that is smooth or finely sculptured proximally, and conspicuously baculate, spinulate or verrucate distally. There is no evidence to support the view that A. baculatus (Archangelsky & Gamerro 1966a, 203–204) has a two-layered exine. Australian spores referred to A. saevus appear to be single-layered (under light-microscope observation), although, in some specimens, fine compressional folds (developed in the thin proximal exine bordering the cingulum) assume the appearance of an inner layer.

The subgeneric concept of Verrucingulatisporites (Treplinisporites) Kedves 1973 (p. 57) is closely equivalent to Antulsporites. However, Verrucingulatisporites Kedves 1961 and Verrucingulatisporites (Verrucingulatisporites) Kedves 1973 are distinguished by well-developed proximal sculpture and distinct equatorial structure. Verrucingulatisporites Hiltmann 1967 is a homonym of Verrucingulatisporites Kedves, and a synonym of Antulsporites.

Affinity.Antulsporites regius (Drozhastchich) McKellar & Cooling comb. nov., as Stereisporites regius (Drozhastchich) Felix & Burbridge 1973, was identified as having an affinity with the Sphagnaceae (Felix and Burbridge 1973), and the genus Antulsporites as a whole as having a Bryophytic affinity (Mohr and Gee 1992).

Antulsporites saevus (Balme) Archangelsky & Gamerro emend. McKellar & Cooling

Plate 8, figs 25–28; Plate 9, figs 1–8; Supplemental Plate 13, figs 11–15, 22, 23

Synonymy.

1957 Cingulatisporites saevus Balme, 26; pl. 4, fig. 57; pl. 5, figs 58–59.

1959 Cingulatisporites granulatus de Jersey, 357; pl. 2, fig. 7.

1966a  Heliosporites saevus (Balme) Archangelsky & Gamerro, 203.

1966a  Heliosporites baculatus Archangelsky & Gamerro, 203–204; pl. 1, figs 12–15.

1966a  Heliosporites granulatus (de Jersey) Archangelsky & Gamerro, 203.

1966c  Antulsporites baculatus (Archangelsky & Gamerro) Archangelsky & Gamerro, 369.

1966c  Antulsporites saevus (Balme) Archangelsky & Gamerro, 369.

1966c  Antulsporites granulatus (de Jersey) Archangelsky & Gamerro, 369.

2002a  Antulsporites saevus (Balme) Archangelsky & Gamerro emend. McKellar, ‘in press’*; Sajjadi & Playford, 72; pl. 14, figs 14–19.

2007 Antulsporites saevus (Balme) Archangelsky & Gamerro emend. McKellar, ‘in press’*; Ribecai, 9.

1998 Antulsporites saevus (Balme) Archangelsky & Gamerro emend. McKellar*, 166–168; pl. 24, figs 18–25; pl. 25, figs 1–7.

*Emendation: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, in press (e.g. Sajjadi and Playford 2002a; Ribecai 2007, above); see explanatory note in Introduction].

Emended diagnosis (after McKellar 1998). Spores radial, trilete, cingulate. Amb subcircular to convexly subtriangular. Laesurae distinct, straight to weakly sinuous; suturae 0.4–0.6 spore radius in length; bordering margo often indistinct, low, flat, uniform or equatorially tapering in width (1.5–3.5 μm wide at pole), extending past termini of suturae and approximating (occasionally reaching onto) cingulum. Cingulum hyaline, laevigate or radially striate, ±uniform, 2–12 μm wide; equatorial outline smooth to irregular (with fracturing). Proximal exine thin, laevigate to finely granulate, often discretely to distinctly sculptured in interradial, subequatorial areas (adjacent to inner margin of cingulum) with low grana, verrucae, bacula, coni, or spinae (<1–5 μm high) possessing discrete to commonly coalescent, subcircular to tangentially elongate bases (<1–3.5 μm in maximum diameter). Sculptural elements situated sublinearly or along margins of a narrow, crescentic area; proximal sculpture sometimes reduces to a curved, continuous or broken murus, 15–18 μm long, 1–1.5 μm wide; rarely, at equivalent radial positions, a small, rounded, ‘pad-like’ thickening occurs superimposed on each laesura (outside extent of suturae). Distal sculpture extremely variable, sometimes consisting ± entirely of one element type (spinae, bacula, coni or verrucae-grana), but more commonly comprising several types, with verrucae-grana usually developed in polar-subpolar area; sculptural elements closely spaced (0.5–4 μm apart), generally increasing in height towards equator, infrequently with an inconspicuous band of fine elements developed adjacent to (and underlying coarse elements projecting over) cingulum. Spinae, coni and bacula radially orientated, 1.5–11.5 μm high; bases generally discrete, subcircular to rounded-elongate in outline, up to 5.5 μm in maximum diameter; apices of coni/spinae acutely rounded to sharp, and of bacula, rounded, truncate or jagged. Verrucae-grana <1–7 μm high; bases discrete to frequently coalescent, subcircular, elongate, polygonal to irregular in outline, up to 7.5 μm in maximum diameter.

Dimensions. Equatorial diameter (64 specimens) 29 (38) 48 μm (McKellar 1998). Equatorial diameter (36 specimens): 28 (38) 56 μm (this study).

Remarks and comparisons. The specific diagnosis has been emended to incorporate forms not only with proximally sculptured exines, but also wider cingula and longer projections than previously recorded (compare: Balme 1957; de Jersey and Paten 1964). So delimited, Antulsporites saevus is considered to be conspecific with, and senior to, A. baculatus, the designated type species of Archangelsky & Gamerro (1966c; compare McKellar 1974, 29).

While the end-members of Antulsporites saevus and A. regius are highly distinct and easily identifiable (e.g. Plate 9, figs 1–2 for A. saevus and Supplemental Plate 13, figs 16–18 for A. regius), as are the majority of specimens, the two taxa do appear to have an intergradational relationship with some specimens showing a more intermediate character (Plate 9 figs 3–5, 7, 8). Compared to Antulsporites saevus, the sculptural elements of A. regius are distinctly and consistently more rounded (subcircular to rounded-elongate) in basal outline, more uniform in size in individual specimens, and often decrease in density towards the equator. In the intermediate forms here assigned to Antulsporites saevus the verrucae-grana have a mixture of subcircular, polygonal and irregular bases and profiles, and typically coarsen towards the equator.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare, and becomes sporadic in the Gubberamunda Sandstone and above.

Previous records. Early Jurassic to Early Cretaceous of Australia (Balme 1957; de Jersey 1959; de Jersey 1963; de Jersey and Paten 1964; Reiser and Williams 1969; McKellar 1974; Filatoff 1975; Kemp 1976; Burger and Senior 1979; Helby et al. 1987; Backhouse 1988; Burger 1989; Burger 1996; McKellar 1998; Sajjadi and Playford 2002a; Mantle 2009; Mantle and Riding 2012).

Antulsporites regius (Drozhastchich) McKellar & Cooling comb. nov.

Supplemental Plate 13, figs 16–18

Synonymy.

1957 Sphagnites clavus Balme (pars), 16; pl. 1, fig. 5 (non figs 4, 6).

1959 Sphagnumsporites clavus (Balme) de Jersey, 348; pl. 1, fig. 2.

1961 Sphagnum regium Drozhastchich in Samoilovitch & Mchedlishvili, 18; pl. 2, figs 1a–d, 2, 3; pl. 64, figs 5–7.

1970 Stereisporites clavus (Balme) Pocock, 34; pl. 6, figs 2–3.

1975 Antulsporites clavus (Balme) Filatoff (pars), 42; text-fig. 15 (top left-hand drawing), (non pl. 2, fig. 4).

2002a  Antulsporites regius (Drozhastchich) McKellar, ‘in press’*; Sajjadi and Playford, 71; pl. 14, figs 11–12.

1998 Antulsporites regius (Drozhastchich) McKellar*, 171–172; pl. 25, figs 12–18; pl. 26, fig. 1.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002a, above); see explanatory note in Introduction].

Dimensions. Equatorial diameter (17 specimens) 26.5 (31) 36.5 μm.

Remarks and comparisons. Spores of Dejerseysporites can resemble Antulsporites regius but have their distal sculpture organised into circular bands of discrete to coalescent sculptural elements. Sculptisporis moretonensis (de Jersey) McKellar & Cooling comb. nov. has a rugulate-granulate, subreticulate-reticulate to foveoreticulate sculpture in place of the granulate-verrucate sculpture of A. regius.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sometimes sporadic.

Previous records. Late Jurassic to Early Cretaceous of Australia (Balme 1957; de Jersey 1959; Filatoff 1975; Sajjadi and Playford 2002a).

Genus Contignisporites Dettmann 1963 

(see Supplemental Appendix for synonymy, type species, and other details)

Contignisporites confractus Cooling sp. nov.

Plate 9, figs 9–14; Supplemental Plate 14, figs 24–29

Synonymy.

1988 Contignisporites glebulentus Dettmann emend. Filatoff & Price (pars), 114, 116, figs 9D–E (non figs 8I–P, 9 C, F–G, K–L; 10 A–H).

1998 Contignisporites sp. A; McKellar*, 230–231; pl. 33, figs 1–3.

*Referred to as Contignisporites sp. A in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Diagnosis. Trilete spores, cingulate. Amb subcircular to convexly subtriangular, often elongated along one axis. Laesurae distinct to indistinct, straight, extending to inner margin of cingulum. Cingulum 3–7 μm thick, smooth to slightly undulate in equatorial outline. Distal sculpture of approximately 6–10 broadly parallel muri that are variably broken into verrucae and rugulae (1.5–6.5 μm wide, 1.5–3 μm high, <0.5–2 μm apart), forming the impression of a subreticulum. Approximate width of four muri plus intervening lumina 12.5–21 μm; Δ-ratio 1.0 (2.6) 3.5. Proximally sculptured with three laevigate muri (2–3 μm wide) in each interradial region near inner margin of cingulum.

Dimensions. Equatorial diameter (19 specimens): 37 (52) 64.5 μm.

Holotype. S16726 Ox GSQ DRD 26 124'2" FHC, S63/2, Plate 9, Figs 11, 12.

Etymology. Latin confractus-a-um, broken, uneven; referring to the broken nature of the distal muri.

Type locality. GSQ DRD 26, 43.3 m, Orallo Formation.

Remarks and comparisons. These spores were first separated from Contignisporites glebulentus by McKellar (1998) because of the broken appearance of their distal muri, which is superficially similar to that of Striatella scanica (Nilsson) Filatoff & Price 1988. However, the distal elements of C. confractus merge with the cingulum and not with a (distal) subequatorial murus, determining assignment of the species to Contignisporites rather than Striatella.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Late Jurassic of Queensland (McKellar 1998).

Genus Dejerseysporites McKellar & Cooling gen. nov.

Synonymy.

1966 Stereisporites (Dicyclosporis) Schulz in Döring et al. (pars), 78.

1966 Stereisporites (Distcyclosporis) Schulz in Döring et al. (pars), 78.

1970 Stereisporites (Annulispora) de Jersey emend. Schulz (pars), 693–694.

2002b  Dejerseysporites McKellar, ‘in press’*; Sajjadi and Playford, 101.

1998 Dejerseysporites McKellar*, 190–191.

*New genus: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, in press (e.g. Sajjadi and Playford 2002a, above); see explanatory note in Introduction].

Type. Dejerseysporites biannuliverrucatus McKellar & Cooling sp. nov.

Diagnosis. Spores radial, trilete, cingulate. Amb subcircular to convexly subtriangular. Cingulum narrow, uniform, laevigate or radially striate. Proximal exine (within cingulum) laevigate. Distal sculpture comprises closely spaced, discrete to coalescent verrucae-grana arranged into one or two annular bands concentric with equator; exine at and about pole laevigate or sculptured with irregularly distributed, discrete or partially coalescent verrucae-grana.

Etymology. After Dr Noel de Jersey, honouring his pioneering contribution to palynology in Queensland and Australia.

Remarks and comparisons. Sculptural elements forming the distal annular bands, although they may be coalescent with adjacent elements within each band, retain their individual character. This feature is considered to be the primary diagnostic character of the genus, allowing separation from morphologically similar genera displaying homogeneous, smooth to radially striate, annular crassitudes on their distal surfaces.

Stereisporites (Dicyclosporis) Schulz (in Döring et al. 1966), which encompasses trilete, cingulate spores ornamented distally with a smooth, radially grooved, or verrucate ring enclosing an unsculptured area about the pole, is partly synonymous with Dejerseysporites, but to the exclusion of its type species, Stereisporites (Dicyclosporis) radiatus Schulz. The latter species, in possessing a single, continuous (radially grooved) distal ring, has been combined with Annulispora de Jersey (McKellar 1974, 24).

Stereisporites (Distcyclosporis) Schulz (in Döring et al. 1966), on the other hand, is characterised by a distal sculpture comprising one or two concentric exinal thickenings that encircle a small group of verrucae situated about the pole. However, although the concept of cyclically arranged verrucae was not specifically included in the diagnosis of Stereisporites (Distcyclosporis), Döring & Schulz (in Döring et al. 1966) combined Sphagnites clavus Balme 1957 (ascribed here to Dejerseysporites) with Schulz’s subgenus. Consequently, in the sense of this usage, Stereisporites (Distcyclosporis) is also partially synonymous with Dejerseysporites. However, its type species, Stereisporites (Distcyclosporis) trizonatus Schulz, which has two radially grooved distal rings, is quite distinct from spores referred to the present genus, having more in common with Polycingulatisporites circulus Simoncsics & Kedves and Taurocusporites segmentatus Stover, respectively the type species of Polycingulatisporites Simoncsics & Kedves 1961 and Taurocusporites Stover 1962. These three species (trizonatus, circulus, segmentatus), unlike those assigned to Dejerseysporites, are characterised by a circumpolar (subequatorial) ridge that is inclined away from the distal pole (Filatoff 1975, 39). The latter author thus regarded Taurocusporites and Stereisporites (Distcyclosporis) as junior synonyms of Polycingulatisporites. Contrastingly, McKellar (1974) favoured retention of all three, restricting each genera to the morphography of their respective type species.

Antulsporites Archangelsky & Gamerro, to which some species recorded hereunder have been assigned previously, is distinguished by its undifferentiated (non-annular) distal sculpture of verrucae, bacula or spinae.

Affinity. Sphagnaceae (Döring et al. 1966; Filatoff 1975).

Other species.

Dejerseysporites verrucyclus (Schulz) McKellar & Cooling comb. nov.

1966 Stereisporites (Dicyclosporis) verrucyclus Schulz in Döring et al. p. 79, pl. 3, figs 16–17.

1970 Stereisporites (Annulispora) verrucycla (Schulz) Schulz, 694, pl. 134, figs 13–18.

1998 Dejerseysporites verrucyclus (Schulz) McKellar*, 192.

*New combination: Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Dejerseysporites biannuliverrucatus McKellar & Cooling sp. nov.

Plate 9, figs 15–22; Supplemental Plate 14, fig. 23

Synonymy.

1974 Antulsporites sp. B; McKellar, 30–31; pl. 8 fig. 20.

2002b  Dejerseysporites biannuliverrucatus McKellar, ‘in press’*; Sajjadi and Playford, 101, pl. 1, fig. 2.

1998 Dejerseysporites biannuliverrucatus McKellar*, 192–194; pl. 27, figs 16–23.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002b, above); see explanatory note in Introduction].

Diagnosis. Spores radial, trilete, cingulate. Amb convexly subtriangular to subcircular. Laesurae distinct; suturae straight to weakly sinuous, rarely enclosed within thin, low, membraneous lips (<1 μm high), extending 0.6–0.8 spore radius; bordering margo low, flat, uniform or equatorially tapering in width (3–5.5 μm wide at pole), sometimes reaching beyond suturae, rarely extending to cingulum. Cingulum laevigate to radially striate; width ± uniform, 1.5–3 μm; equatorial outline smooth. Proximal exine (within cingulum) laevigate. Distal sculpture comprises low verrucae-grana (1.5–7.5 μm in maximum diameter; subcircular, rounded-elongate, or irregular in basal outline) arranged into: (i) a small group of closely spaced, infrequently coalescent elements situated at and about pole; (ii) a subpolar annular band (3.5–4 μm wide) of coalescent and discrete elements enclosing the polar sculpture and situated 0.3–0.5 spore radius from pole; and (iii) a subequatorial annular band (4–7 μm wide) of predominantly to completely coalescent elements concentric with subpolar band and amb, and situated 0.6–0.8 spore radius from pole.

Dimensions. Equatorial diameter (45 specimens) 30 (40) 49 μm (McKellar 1998). Equatorial diameter (7 specimens): 23.5 (31.5) 42 μm (this study).

Holotype. Slide A1972/2, G54/0; Q553; Plate 9, Fig. 15.

Type locality. GSQ Roma 8, 780.10 m, Hutton Sandstone.

Etymology. Latin: bis, twice; annŭlus-i (m), a ring; verrūca-ae (f), a wart; referring to the distal sculpture.

Remarks and comparisons. Infraspecific variation includes the distal subpolar band, although generally distinct overall, is variable in its development, depending on the degree of coalescence of the verrucae-grana comprising it. In individual specimens, this band is usually not as well-developed as the enclosing subequatorial annulus.

Representatives in which the elements forming the subpolar band are predominantly discrete bear a close resemblance to, and are probably intergradational with, D. verrucosus (Pocock) comb. nov. The latter species is distinguished by the occurrence of a single, distal, subequatorial band of verrucae-grana. Further, the subequatorial band of D. biannuliverrucatus is usually better developed, with greater fusion of elements, than the equivalent structure in D. verrucosus.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Late Early to Late Jurassic of Queensland (McKellar 1974; McKellar 1979; McKellar 1981b; McKellar 1998; Sajjadi and Playford 2002b).

Dejerseysporites verrucosus (Pocock) McKellar & Cooling comb. nov.

Supplemental Plate 14, figs 19–22

Synonymy.

1969 Antulsporites varigranulatus (auct. non Levet-Carette) Reiser & Williams, 11; pl. 4, figs 8–9.

1970 Distalanulisporites verrucosus Pocock, 59; pl. 6, figs 4, 7.

2002b  Dejerseysporites verrucosus (Pocock) McKellar, ‘in press’*; Sajjadi and Playford, 101–102; pl. 1, fig. 3.

1998 Dejerseysporites verrucosus (Pocock) McKellar*, 194–195; pl. 27, fig. 24; pl. 28, figs 1–3.

See Sajjadi and Playford (2002b, 101) for additional synonymy.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002b, above); see explanatory note in Introduction].

Dimensions. Equatorial diameter (14 specimens): 25 (29.5) 43.5 μm.

Remarks and comparison. Reiser and Williams (1969, 11), in their description of the species, noted that the proximal exine, although usually laevigate, may be ornamented with sparsely distributed verrucae and grana. In the study of McKellar (1998) only unsculptured proximal surfaces were recorded (also McKellar 1974; Filatoff 1975), while a small number of those observed in this study (also Sajjadi and Playford 2002b), were observed to have sparse proximal grana and verrucae.

Dejerseysporites verrucosus is conspecific with spores assigned to Polypodiaceoisporites minor Kedves (1961, 138; pl. 7; figs 27–28) by Levet-Carette (1963), but it is not clear from Kedves’ diagnosis and photomicrographs whether his species is delimited by the same morphographic features. Antulsporites varigranulatus (Levet-Carette) Reiser & Williams (see synonymy) is clearly distinct, displaying distal sculpture lacking cyclic arrangement. Moreover, Levet-Carette’s species is a possible synonym of Antulsporites regius (Drozhastchich). Closely allied spores of D. biannuliverrucatus are distinguished by the development of two concentric annular bands (subpolar and subequatorial) on the distal surface.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Late Triassic to Early Cretaceous of Australia (Playford and Cornelius 1967; Reiser and Williams 1969; de Jersey 1971b; de Jersey 1971a; McKellar 1974; Filatoff 1975; McKellar 1975; McKellar 1978b; McKellar 1978c; McKellar 1978a; McKellar 1978d; McKellar 1979; McKellar 1981b; McKellar 1981a; Burger 1989; Burger 1996; McKellar 1998; Sajjadi and Playford 2002b).

Genus Interulobites Paden Phillips in Paden Phillips & Felix 1971 

Synonymy.

1971 Interulobites Paden Phillips in Paden Phillips & Felix, 328.

Remarks and comparison.Interulobites Paden Phillips encompasses trilete, cingulate spores sculptured distally with verrucae, rugulae or bacula, and with a proximal surface that is either smooth or displays reduced sculpture. Nevesisporites de Jersey & Paten, a closely allied genus, is distinguished by its distinctly sculptured proximal hemisphere.

Interulobites scabratus McKellar & Cooling sp. nov.

Plate 9, figs 23–28; Supplemental Plate 15, figs 12, 13

Synonymy.

1998 Interulobites scabratus McKellar*, 209–210; pl. 29, figs 3–9.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Diagnosis. Spores radial, trilete, cingulate. Amb subcircular to convexly subtriangular. Laesurae distinct to indistinct, straight to weakly sinuous, extending between 0.8 spore radius and equator; enclosed within weakly elevated lips and bordered by a low, weakly tapering margo (1–3.5 μm wide at pole). Cingulum ± uniform in width (1.5–5 μm). Exinal surface (including cingulum) scabrate to very finely subreticulate, only visible when viewed with a high-powered oil-immersion lens; contact faces indistinctly granulate in some specimens. Distal surface occasionally bears hollow, low, discrete to coalescent verrucae-rugulae irregularly distributed about pole (5.5–18 μm in maximum diameter).

Dimensions. Equatorial diameter (34 specimens) 36 (47) 58 μm (McKellar 1998). Equatorial diameter (54 specimens): 34 (48.5) 62.5 μm (this study).

Holotype. Slide A285/2, F24/1; Q577; Plate 9, Figs 25, 26.

Type locality. GSQ DRD 24, 131.11 m, Hutton Sandstone.

Etymology. Latin: scăbrātus-a-um, roughened; referring to the generally scabrate nature of the exinal surface.

Remarks and comparisons. One poorly preserved specimen recorded in McKellar (1998) suggests that the finely subreticulate character of the exinal surface is representative of a closely attached, membraneous, outer layer. By implication, closely allied spores of Nevesisporites vallatus de Jersey & Paten emend. and Foraminisporis dailyi (Cookson & Dettmann), with similar fine surface features, may be constructed in a like manner.

Nevesisporites vallatus is distinguished by its distinctly sculptured proximal surface and its ‘zipper-like’ margo. Interulobites triangularis (Brenner) Paden Phillips 1971 is closely comparable with I. scabratus sp. nov. but lacks the scabrate-subreticulate surface of the latter. Its proximal surface is smooth (Brenner 1963, 65), or ‘mostly smooth, with a very few round granules’ (Paden Phillips in Paden Phillips and Felix 1971, 329), and lacks thickening of the laesurate margins.

Polycingulatisporites liassicus Schulz 1967 (587, pl. 14, figs 7–9; pl. 23, fig. 5) and spores referred to Distalanulisporites spurius (Bolkhovitina) by Pocock (1970, 58, pl. 10, figs 10–11) can also be compared closely with I. scabratus. However, Schulz’s species has curvaturae associated with its laesurae and distal verrucae mostly concentrated in a ring, a feature not observed in the present species. Pocock’s material, on the other hand, displays two types of verrucae distally: (i) small, rounded elements; and (ii) larger, irregularly rounded, hollow elements, which show some tendency to form annular zones parallel to the equator.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Late Jurassic of Queensland (McKellar 1998).

Genus Nevesisporites de Jersey & Paten emend. McKellar & Cooling

Synonymy.

1964 Nevesisporites de Jersey & Paten, 8.

1970 Simeonospora Balme*, 329–330.

1971 Asterisporites Venkatachala & Rawat, 106–107.

1972 Nevesisporites de Jersey & Paten; Srivastava, 25–26.

1973 Trisolissporites Tschudy, 8–9.

1975 Nevesisporites de Jersey & Paten emend. Morbey, 19.

1979 Limatulasporites Helby & Foster** in Foster, 50–51.

1983 Gordonispora van der Eem (pars?), 253.

1998 Nevesisporites de Jersey & Paten; Backhouse (pars), 63–64.

1998 Nevesisporites de Jersey & Paten emend. McKellar***, 201–204.

*Sajjadi and Playford (2002b, 106) regard the synonymising of Simeonospora Balme by McKellar (‘in press’***) with Nevesisporites as untenable, based on the development of curvaturae in Simeonospora khlonovae Balme (the type species of the former, although such features were not referred to in the attendant generic diagnosis). However, McKellar’s (1998) PhD assessment was not disputed by Dr B.E. Balme, the author of the genus and an examiner of his thesis. This is also in agreement with the synonymising by Srivastava (1972, 25).

**Also see comments of de Jersey and Raine (1990, 38).

***Emendation: Validly published here. Originally proposed in McKellar’s (1998) PhD thesis and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Type. Nevesisporites vallatus de Jersey & Paten emend. McKellar & Cooling; original designation.

Emended diagnosis. Spores radial, trilete, cingulate. Amb convexly subtriangular to subcircular. Laesurae extending to, or almost to, equator; enclosed within slightly elevated lips. Proximal sculpture variably developed (sometimes greatly reduced), generally comprising grana, verrucae and/or rugulae restricted to laesurate margins and interradial polar-subpolar areas, or more widely distributed, either irregularly or radially about centre of each contact face. Remainder of proximal surface and entire distal surface laevigate, scabrate, or very finely granulate-rugulate to irregularly subreticulate; distal hemisphere may bear: (i) polar and circumpolar crassitudes, or (ii) grana, verrucae and rugulae, either irregularly distributed or arranged in a regular pattern (concentrically/radially) about the pole.

Remarks and comparisons.Nevesisporites de Jersey & Paten has been emended primarily to encompass the extremely wide range of morphological variation described here in its type species. Additional features displayed by other taxa assigned to the genus have also been incorporated. However, the generic circumscription has not been extended to include spores like Foraminisporis dailyi (Cookson & Dettmann), a Late Jurassic – Early Cretaceous Australian species closely related to N. vallatus and distinguished only proximally from certain variants of the latter by the development of a small cluster of grana or verrucae at the centre of each contact face (compare Backhouse 1988, pp.63–64).

Stoverisporites Burger 1976 is another closely allied genus characterised by a distal sculpture variously described as pits, lumina, foveolae and depressions (Kemp in Kemp and Harris 1970; Burger 1976). This distal sculpture contrasts with the verrucae and other projections on the distal hemisphere of Nevesisporites. However, detailed and extensive observations in the Late Jurassic – Early Cretaceous of the Surat Basin (McKellar 1998, unpublished data) suggest that the hollow, distal sculptural projections of N. vallatus and F. dailyi may have given rise to the circular to oval lumina of Stoverisporites, as indicated by specimens with apparent intermediate morphology (see remarks under N. vallatus, and F. dailyi in the Supplemental Appendix). Based on this, and striking similarities of proximal sculpture and equatorial structure, a close relationship is suggested between the Late Cretaceous type species S. microverrucatus Burger and N. vallatus. A similar relationship is also likely between F. dailyi and both S. lunaris (Cookson & Dettmann) Burger, from the Early Cretaceous – Cenomanian of Australia, and S. verrucolabrus Kemp 1977, from the Early Tertiary of Ninetyeast Ridge in the Indian Ocean.

Broadly comparable genera such as Antulsporites Archangelsky & Gamerro and Dejerseysporites gen. nov. lack the generally distinct, although variable proximal sculpture of Nevesisporites. Certain Devonian spores associated with Emphanisporites McGregor [viz., E. erraticus (Eisenack) McGregor, (1961, 4; pl. 1; figs 7–11)] display a superficial resemblance to Nevesisporites, as proximal ridges in each interradial area tend to converge at a locus about three-quarters of the distance from the equator to the pole. However, in the Devonian type species of McGregor’s genus (E. rotatus McGregor), radially disposed thickenings extend from the proximal pole to the equator, thus providing differentiation from the present genus.

Affinity. Almost certainly Bryophytes: Anthocerotophyta. The extremely close morphological relationships between Nevesisporites, Foraminisporis and Interulobites suggests that they are certainly all of bryophytic origin.

Other species.

Nevesisporites minutus (Jansonius) McKellar & Cooling comb. nov.

1962 Dulhuntyispora? minuta Jansonius, pp.48–49, pl. 11, figs 1–5.

1973 Trisolissporites minutus (Jansonius) Tschudy, 9.

1998 Nevesisporites minutus (Jansonius) McKellar*, 202.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Nevesisporites granulatus (Schulz) McKellar & Cooling comb. nov.

1967 Carnisporites granulatus Schulz, 567, pl. 4, figs 17–19.

1998 Nevesisporites granulatus (Jansonius) McKellar*, 202.

See Rogalska (1980, 65) for additional synonymy.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Nevesisporites annakhlonovae McKellar & Cooling nom nov.

1970 Simeonospora khlonovae Balme, 330, fig. 4, pl. 2, figs 3–6.

1998 Nevesisporites annakhlonovae McKellar*, pp.202–203.

*New name: Validly instituted here. Originally proposed in an unpublished PhD thesis and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Remarks. Balme’s species is renamed as it is interpreted as a later homonym of Taurocusporites chlonovae Döring 1966. Simeonospora Balme is a synonym of Nevesisporites (also Srivastava 1972a, 25) and T. chlonovae a junior synonym of N. vallatus (see below).

Nevesisporites vallatus de Jersey & Paten emend. McKellar & Cooling

Plate 10, figs 1–12; Supplemental plate 15, figs 19–21

Synonymy.

1964 Nevesisporites vallatus de Jersey & Paten, 8–9; pl. 5, figs 11–15; pl. 6, figs 1–2.

1966 Taurocusporites chlonovae Döring, pp.105–106; pl. 1, figs 7–9.

1981 Cingutriletes cestus Stevens (pars), 20–21; pl. 4, figs 8–9 (non pl. 4, figs 7).

1988 Nevesisporites harleyi Backhouse, 64; pl. 7, figs 14–17; pl. 14, figs 4–5.

1988 Nevesisporites undatus Backhouse (pars), 64; pl. 14, fig. 8 (non pl. 8, figs 1–3; pl. 14, figs 6, 7, 9, 10).

1998 Nevesisporites vallatus de Jersey & Paten emend. McKellar*, 204–207; pl. 28, figs 14–21; pl. 29, figs 1–2.

*Emendation validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Emended diagnosis. Spores radial, trilete, cingulate. Amb subcircular to convexly subtriangular. Laesurae distinct, straight to weakly sinuous, extending to inner margin of cingulum, sometimes reaching equator, occasionally with terminal bifurcation; enclosed within weakly raised commissures and bordered by a margo. Cingulum ± uniform in width (2–6 μm wide); equatorial outline generally smooth. Proximal sculpture comprises grana and verrucae, commonly also rugulae, rarely subconi-coni. Grana/verrucae low (<1.5 μm high), subcircular, elongate to irregular in basal outline (<1–3.5 μm in maximum diameter); rugulae intergradational with verrucae, ca. 1–1.5 μm wide, <9 μm in length; subconi-coni <2.5 μm high, 1–1.5 μm in basal diameter. Sculptural elements closely spaced (<1–1.5 μm apart), comprehensively or partly distributed over proximal face (rarely extending on to cingulum), commonly confined to interradial polar-subpolar areas and radii, or restricted to the latter; along laesurate margins, usually elongate and orientated ± perpendicularly, with bases discrete to variably coalescent, forming a margo generally with a ‘zipper-like’ appearance; and, in interradial areas, either irregularly distributed or orientated about centre of each contact face with radiating lines of discrete to partially fused grana, verrucae and rugulae (intimately associated with orientation of elements along laesurate margins). Proximal exine otherwise laevigate, scabrate or very finely granulate-rugulate to subreticulate. Distal surface laevigate or sculptured with sparse to closely spaced grana-verrucae and occasional fold-like rugulae; otherwise scabrate or very finely granulate-rugulate to subreticulate. Sculptural elements <3 μm high, subcircular, elongate or irregular in overall basal outline (1–12 μm in maximum dimension), sometimes appearing hollow; discrete to moderately coalescent, distributed over distal surface either irregularly or in: (i) a small group (rarely only a single, large verruca) centred on the pole; and (ii) an enclosing annular arrangement grading into a ± continuous, ridge-like crassitude (1.5–5.5 μm wide) concentric with cingulum, with its outer margin situated 0.6–0.7 spore radius from pole.

Dimensions. Equatorial diameter (103 specimens) 34 (47) 58 μm (McKellar 1998). Equatorial diameter (62 specimens): 23.5 (51.5) 63 μm (this study).

Remarks and comparisons. The specific concept of N. vallatus has been widened to encompass the morphologically extensive and continuous variation documented here (compare de Jersey and Paten 1964). The morphologic variants cannot be readily isolated stratigraphically, although forms with distinctly hollow, distal elements and others with extremely reduced sculpture (±finely subreticulate overall, with a few grana, etc. bordering the laesurae) occur more commonly in, but are not confined to, the higher parts of the Surat Basin succession (Orallo Formation–Mooga Sandstone). There, they generally lack the robust character displayed by examples from lower stratigraphic levels in the Injune Creek Group. Moreover, as the variation in Middle – Late Jurassic assemblages from the Hutton Sandstone and Injune Creek Group extends into spores with wide cingula (3–5 μm wide), although infrequently, N. harleyi Backhouse (1988), described from the Tithonian and Early Cretaceous of Western Australia, is regarded as a synonym.

The development and general appearance of the hollow sculptural elements (usually verrucae, also verrucae-rugulae) in specimens of N. vallatus [also Foraminisporis dailyi] is extremely variable (see remarks under generic heading above). Under the light microscope, some spores appear to have both hollow and solid elements distally, whereas others, only one type or the other. Without critical TEM examination, such differences between these elements, to some extent, may be more apparent than real, perhaps being a reflection of preservational history (degree of carbonisation) and/or minor exinal changes up section, with the development of thinner and less rigid sculptural surfaces. In the lower parts of the Surat Basin succession, possibly because of the above, the nature of the distal surface and of the sculpture thereon (if any) is more difficult to determine, even with oil-immersion microscopy. Detailed observation of same is further hindered by the almost invariable orientation of specimens with their proximal surfaces uppermost. Additionally, hollow verrucae on specimens from the Orallo Formation and Mooga Sandstone are sometimes improperly formed or compressed, and are represented: (i) at the spore surface by a slightly raised rounded area of exine, either partially or entirely surrounding a small depression; and (ii) in optical section by a ring-, cresentic- or U-shaped appearance. In some instances, their formation appears extremely rudimentary, and, under the light microscope, they appear to be gradational into the element type (pits, lumina) described on the distal surface of Stoverisporites microverrucatus and S. lunaris [see remarks under Foraminisporis dailyi].

The majority of spores described above, which were selected randomly throughout the section examined, are granulate-verrucate distally, although, in most cases, only indistinctly so. Contrastingly de Jersey and Paten’s (1964) type specimens and numerous other specimens in associated microslides, upon re-examination, yielded no evidence of distal sculpture, but they are poorly preserved.

In representatives with a well-defined radiating pattern centred on each contact face, the individual radial rays are represented by lines of grana, verrucae and short rugulae (Plate 10, figs 2, 3, 7–9). The pattern of radiating, continuous (occasionally bifurcating) rugulae present in the proximal interradial areas of N. radiatus (Chlonova) Srivastava appears to be a post-Jurassic development and distinguishes N. vallatus from Chlonova’s species (compare Srivastava 1972). In the former U.S.S.R., spores of the ‘radiata’ type occur in great quantities in deposits dated as Cenomanian–Turonian; they appear as occasional specimens in probably Aptian–Albian strata and disappear in the Senonian (Chlonova 1962, 302). In Australia, spores similar to N. radiatus have been observed in Cenomanian palynofloras from Bathurst Island, Northern Territory (M.E. Dettmann, personal communication).

Nevesisporites vallatus is distinguished from Foraminisporis dailyi by the occurrence in the latter species of a small group of grana-verrucae at the centre of each contact face. Stoverisporites microverrucatus Burger (1976, 119, pl. 19, figs 3–4), from the Cenomanian of Bathurst Island, has a smaller, although overlapping size range (24–43 μm), but is otherwise comparable with those representatives of N. vallatus that display poorly formed, hollow verrucae distally.

Spores presumably allied with the present species first appeared in Permian and Triassic strata. Nevesisporites fossulatus Balme (1970), which was described originally from the Late Permian of Pakistan, is smaller than N. vallatus and has a single, subcircular, polar thickening distally. Nevesisporites annakhlonovae nom nov. (=Simeonospora khlonovae Balme 1970; see ‘Other species’ above), from the Early Triassic of Pakistan, is differentiated by its larger size and the development of clearly defined, markedly depressed contact areas bearing radial sculpture broadly comparable with that of N. vallatus. The Australian Triassic species, N. limatulus Playford (1965, 188–189; pl. 8; figs 16–19), closely resembles N. vallatus, but its proximal sculpture is ‘exclusively and uniformly granulate’, and lacks the orientation of elements described in both the radial and interradial areas of the latter. Nevesisporites undatus Backhouse (1988, 64, pl. 8, figs 1–3; pl. 14, figs 6–10), from Tithonian and Early Cretaceous strata of the Perth Basin (Western Australia), is characterised generally by the radial character of its distal sculpture. However, variants of the species lacking this feature and displaying randomly distributed elements distally are more difficult to differentiate from N. vallatus.

Nevesisporites bigranulatus (Levet-Carette) Morbey, recorded by Levet-Carette (in Rioult and Levet-Carette 1966, 290) from the Infra-Lias of France, is also difficult to distinguish from distally sculptured specimens of N. vallatus, but appears to lack the ‘zipper-like’ laesurate features generally associated with de Jersey and Paten’s species. Nevesisporites granulatus (Schulz) comb. nov. (described from the Middle Keuper to Liassic of Germany; Schulz 1967, 567, pl. 4, figs 17–19) possesses a distinctly irregular proximal sculpture. A specimen figured as Interulobites intraverrucatus (Brenner) by Wingate (1980, 26; pl. 10; fig. 3; compare Brenner 1963) has proximal sculpture not unlike that of N. vallatus.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Early Jurassic to Early Cretaceous of Australia (de Jersey and Paten 1964; Paten 1967; Reiser and Williams 1969; de Jersey 1971a; Burger 1974; McKellar 1974; Backhouse 1975; Filatoff 1975; Backhouse 1978; McKellar 1978d; McKellar 1978c; McKellar 1978a; Burger and Senior 1979; Morgan 1980; McKellar 1981b; Helby et al. 1987; Backhouse 1988; McKellar 1998; Sajjadi and Playford 2002b; Mantle 2009; de Jersey and McKellar 2013).

Genus Sculptisporis (Döring & Schulz) McKellar & Cooling stat. nov.

Synonymy.

1966 Stereisporites (Sculptisporis) Döring & Schulz in Döring et al. p. 76.

2002b  Sculptisporis (Döring & Schulz) McKellar ‘in press’*; Sajjadi and Playford, 109.

1998 Sculptisporis (Döring & Schulz) stat. nov. McKellar*, pp.183–184.

*Elevation to generic rank: Validly published here. Originally proposed in an unpublished PhD thesis by McKellar (1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002b, above); see explanatory note in Introduction].

Type. Sculptisporis hauterivensis (Döring in Döring et al.) McKellar & Cooling; original designation [after Döring and Schulz’s original designation of this species as type for Stereisporites (Sculptisporis) as a subgenus].

1966 Sterisporites (Sculptisporis) hauterivensis Döring in Döring et al. p. 77; pl. 3, figs 1–3.

Remarks and comparisons.Sculptisporis, instituted by Döring and Schulz as a subgenus of Stereisporites Pflug, is elevated to generic rank, and its designated (subgeneric) type species is accordingly recombined with Sculptisporis at the generic level.

The identical change in status proposed for Stereisporites (Sculptisporis) by Kedves & Herngreen (1980, 492) is considered to be invalid, as it was not accompanied by a description or diagnosis of the genus, or by reference (direct or indirect) to a previously and effectively published description or diagnosis of the genus in that rank or as a subdivision of a genus (Articles 32, 41.2 Greuter 1994).

The generic diagnosis given hereunder is based closely on the original subgeneric concept, but with some amplification of its equatorial and laesurate features (compare Döring and Schulz in Döring et al. 1966, pp.76–77, pl. 3, figs 1–11).

Sculptisporis is readily differentiated from Foveosporites Balme (1957) by its distinctive laesurae and proximally smooth exine. Annulispora de Jersey has equatorial and laesurate features identical with those of Sculptisporis, but, distally, it is clearly distinct.

Diagnosis. Spores radial, trilete. Amb convexly subtriangular to subcircular. Suturae 0.5–0.8 spore radius; bordering margo low, equatorially tapering, extending beyond suturae to equator. Exine with or without slight equatorial thickening (cingulate to acingulate); foveolate, foveoreticulate, corrugate or hamulate distally; laevigate proximally.

Affinity. Bryophytes: Sphagnaceae (Döring et al. 1966; Filatoff 1975).

Sculptisporis moretonensis (de Jersey) McKellar & Cooling comb. nov.

Supplemental Plate 16, figs 1–5

Synonymy.

1964 Foveosporites moretonensis de Jersey, 7; pl. 1, figs 7, 8.

1974 Polypodiaceoisporites tortuosus McKellar, 35–36; pl. 9, figs 13–15.

2002b  Sculptisporis moretonensis (de Jersey) McKellar, ‘in press’*; Sajjadi and Playford, 109–110; pl. 2, figs6–8.

1998 Sculptisporis moretonensis (de Jersey) McKellar*, 184–185; pl. 27, figs 3–8.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002b, above); see explanatory note in Introduction].

Description. Trilete spores, cingulate to acingulate. Amb circular to convexly subtriangular. Laesurae straight, distinct, 0.4–0.8 spore radius in length; equatorially tapering margo 1.5–3 μm wide at pole, may extend beyond the laesurae towards the inner margin of the cingulum. Exine 0.5–2.5 μm thick, uniform. Distally sculptured with bifurcating and anastomosing, low muri (0.5–4 μm wide) forming an irregular subreticulum with lumina 0.5–1.5 μm, rarely up to 2.5 μm wide, up to 6 μm long. Proximally laevigate.

Dimensions. Equatorial diameter (57 specimens): 24 (32) 57.5 μm.

Remarks and comparisons. Distally, Sculptisporis moretonensis (de Jersey) varies in the degree of width and separation of the muri. On some specimens, the muri are most distinct in the distal polar region and become indistinct towards the equator. Some specimens exhibit slightly asymmetrical laesurae. Antulsporites regius is closely comparable, but has a granulate-verrucate distal sculpture.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Latest Triassic to Cretaceous of Australia (de Jersey 1964; Reiser and Williams 1969; de Jersey 1971b; de Jersey 1971a; McKellar 1974; Filatoff 1975; McKellar 1978d; McKellar 1978c; McKellar 1978b; Burger 1980; McKellar 1980; McKellar 1981b; Backhouse 1988; McKellar 1998; Backhouse and Balme 2002; Sajjadi and Playford 2002b; Mantle 2009; Mantle and Riding 2012; de Jersey and McKellar 2013; McLoughlin et al. 2014).

Suprasubturma LAMINATITRILETES Smith & Butterworth 1967 

Subturma ZONOLAMINATITRILETES Smith & Butterworth 1967 

Infraturma CINGULICAVATI Smith & Butterworth 1967 

Genus Densoisporites Weyland & Krieger emend. Bharadwaj & Kumar 1972

(see Supplemental Appendix for synonymy, type species, and other details)

Densoisporites filatoffii McKellar & Cooling sp. nov.

Plate 10, figs 13–35; Supplemental Plate 16, figs 19–27

Synonymy.

1975 Densoisporites sp. A; Filatoff (pars?), 46–47, pl. 4, figs 5–7.

1998 Densoisporites filatoffii McKellar*, 238–239; pl. 33, figs 10–14; pl. 34, figs 3–11.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Diagnosis. Spores radial, trilete, cingulate. Amb convexly subtriangular to subcircular.

Laesurae distinct to indistinct, straight to weakly sinuous, extending between 0.8 spore radius and equator; enclosed within weakly thickened, slightly elevated lips (<1.5 µm high); equatorial termini commonly inconspicuous, sometimes appearing as wider, flattened areas of thicker exine. Exine two-layered, usually acavate to weakly cavate equatorially (separation rarely exceeding 2 µm). Intexine laevigate, <1 µm thick, occasionally folded. Exoexine distinctly to indistinctly cingulate, 1.5–4 µm thick equatorially; distally ± scabrate or sculptured with irregularly interconnected, narrow channels (<l–4 µm apart) and/or shallow, closely spaced pits (<l µm to rarely 2 µm in diameter); proximally: (i) laevigate, (ii) very finely and comprehensively sculptured, or (iii) with sculpture restricted to the equatorial regions.

Dimensions. Equatorial diameter (62 specimens) 29 (38) 49 µm (McKellar 1998). Equatorial diameter (45 specimens): 24 (34.5) 46 μm (this study).

Holotype. Slide S8876, T27/0; Q629; Plate 10, Figures 16–17.

Type locality. GSQ DRD 22, 26.75 m, Walloon Coal Measures.

Etymology. Named after Dr J. Filatoff who figured and informally described the species from the Perth Basin, Western Australia (see synonymy).

Remarks and comparisons. The species displays a moderately wide range of morphological variation. Shallow, close pitting of the exine at one extreme contrasts with the development of narrow and variably spaced channels at the other. Intermediate forms are gradational between these limits, possessing both pits and channels. Perth Basin spores assigned to Densoisporites sp. A were more narrowly circumscribed by Filatoff as being generally smooth or possessing only fine, irregular pitting on their exoexinal surfaces. Densoisporites circumundulatus is distinguished by a radially folded exoexine and an undulate equatorial margin, and D. velatus, by a generally larger size, finely reticulate (spongeous) exoexine, and the occurrence of proximal interradial papillae, although infrequently discernible (see Supplemental Appendix for comments on both species).

Occurrences (Cooling 2020). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Jurassic and Early Cretaceous of Australia (Filatoff 1975; McKellar 1998).

Genus Perotrilites Erdtman ex Couper emend. Evans 1970

(see Supplemental Appendix for type species and other details)

Perotrilites cameronii McKellar sp. nov.

Plate 11, figs 1–13; Supplemental Plate 17, figs 13–15

Synonymy.

1998 Perotrilites cameronii McKellar*, 245–247; pl. 35, fig. 16; pl. 36, figs 1–6; pl. 37, figs 1–3.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript.

Diagnosis. Spores radial, trilete, zonate. Amb convexly subtriangular to subcircular. Laesurae indistinct to distinct, straight to sinuous, extending to equator, enclosed within weakly elevated lips (<4 μm high). Exine two-layered, acavate, rarely cavate. Intexine thin (<1 μm thick), laevigate(?). Exoexine moderately thick; zona membraneous, distinctly thickened at inner margin, occasionally traversed by radially orientated ridges or folds, ±uniform to slightly variable in width (6–17 μm wide), generally irregular in equatorial outline. Distal exoexine (including zona) sculptured with moderately fine to very coarse subconi-coni, less commonly with subbaculate-baculate/subspinulate-spinulate projections (<1–10 μm in overall height); bases rounded, expanded, <1–6.5 μm in diameter, infrequently hollow, discrete (spaced up to 7 μm apart) or variably coalescent (irregularly in groups or in sublinear to subreticulate patterns), occasionally reduced to verrucae-grana; sculptural elements generally coarsest at equatorial margin of spore body, less prominent on distal surface of zona. Equatorial (zonal) margin with reduced sculpture. Proximal exoexine (including zona) scabrate to punctate-reticulate (corrosion) or finely sculptured with discrete or partly coalescent grana and occasional subconi-coni.

Dimensions. Equatorial diameter (62 specimens) 46 (64) 86 μm (McKellar 1998). Equatorial diameter (2 specimens): 61, 64 μm (this study).

Holotype. Slide S8862, X33/0–X33/3; Q654; Plate 11, Figs 1, 2.

Type locality. GSQ DRD 22, 142.57 m, Hutton Sandstone.

Etymology. JLMcK: After my son, Cameron Andrew McKellar.

Remarks and comparisons.Perotrilites cameronii exhibits moderately wide variation in: (i) the width of its equatorial zona; (ii) the composition of its distal sculpture; and (iii) the coarseness, density and basal coalescence of elements constituting the latter.

The species, in part, superficially resembles coarsely sculptured specimens of Aequitriradites acusus (Balme) Dettmann 1963 (e.g. Backhouse 1988, pl. 1, figs 2a–b), but is differentiated by the development of functional laesurae and the absence of a distal hilum and relatively long, proximally situated, sculptural projections. Perotrilites whitfordensis (below) is distinguished by the thinner exoexine of its spore body, which is less coarsely sculptured distally, although its zonal margin is more coarsely and distinctly sculptured than is the case with the present species.

Occurrences (Cooling2020 ). Upper Westbourne Formation – Orallo Formation; rare and sporadic.

Previous records. Late Jurassic of Queensland (McKellar 1998).

Perotrilites whitfordensis (Backhouse) McKellar & Cooling comb. nov.

Plate 11, figs 14–24; Supplemental Plate 17, figs 8–11

Synonymy.

1988 Kraeuselisporites whitfordensis Backhouse, 60; pl. 6, figs 4–6; pl. 13, fig. 7.

1998 Kraeuselisporites whitfordensis (Backhouse) McKellar*, 244; pl. 35, figs 5–15.

*New combination: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Dimensions. Equatorial diameter (45 specimens): 22 (54.5) 98 μm. Equatorial diameter inner (32 specimens): 19.5 (44.5) 67.5 μm.

Remarks and comparisons.Perotrilites whitfordensis (Backhouse) is variable in appearance in this study, possibly at least partially due to the quality of its preservation. Some specimens have well preserved coni and spinae, whereas, in others, only the degraded bases of the sculptural elements (or their imperfectly formed representations) are faintly visible. Some specimens (e.g. Plate 11, figs 19–20), show either a pattern of differential corrosion/wearing or a reduction in the distal sculpture from the pole to the equator. These specimens have distinctly visible sculptural elements across much of the distal surface, but a largely or entirely smooth and non-denticulate amb. Determining the true cause of this pattern was not possible based on the specimens observed as part of this study, though this pattern of sculpture does appear to be akin to one of the specimens figured by Backhouse when the species was first described (1988, Pl. 13, fig. 7).

Distinctly trilete specimens of P. whitfordensis can resemble Aequitriradites norrisii Backhouse 1988, although the latter is hilate and typically has a distinctive trilete mark with three narrow, membranous ridges enclosing a subtriangular polar area. Poorly preserved or orientated members of both P. whitfordensis and Januasporites spinosireticulatus McKellar & Cooling sp. nov. can become indistinguishable if neither the proximal nor distal poles are observable to check for these features.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic, particularly in the upper range.

Previous records. Middle Jurassic to Early Cretaceous of Western Australia (Backhouse 1988; Mantle 2009); Late Jurassic of Queensland (McKellar 1998).

Turma MONOLETES Ibrahim 1933 

Suprasubturma ACAVATOMONOLETES Dettmann 1963 

Subturma AZONOMONOLETES Luber 1935

Infraturma SCULPTATOMONOLETI Dybová & Jachowicz 1957

Genus Marattisporites Couper 1958 

(see Supplemental Appendix for synonymy, type species, and other details)

Marattisporites arcus (Balme) McKellar & Cooling comb. nov.

Plate 11, figs 25–31; Supplemental Plate 18, figs 1–3

Synonymy.

1957 Polypodiidites arcus Balme, 28; pl. 6, figs 67–68.

1963 Reticuloidosporites arcus (Balme) Dettmann, 86; pl. 19, figs 12–14.

1998 Marattisporites arcus (Balme) McKellar*, 251; pl. 36, fig. 16; pl. 37, figs 4–6.

*New combination: Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002b); see explanatory note in Introduction].

Dimensions. Length (64 specimens): 22.5 (33) 47.5 μm. Breadth (64 specimens) 21.5 (26) 32 μm.

Remarks and comparison.Marattisporites arcus is differentiated from M. scabratus by its thicker exine, generally larger size, and coarser, more distinct sculpture.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon, particularly sporadic in the Westbourne Formation.

Previous records. Jurassic to Early Cretaceous of Australia (Balme 1957; Dettmann 1963; Burger 1968; Burger 1974; Backhouse 1988; Burger 1989; Burger 1996; McKellar 1998; Sajjadi and Playford 2002b); Cretaceous of New Zealand (Mildenhall 1977).

Genus Tuberculatosporites Imgrund ex Potonié & Kremp 1954 

Type. Tuberculatosporites anicystoides Imgrund 1960; subsequently designated by Potonié and Kremp (1954, 166). For a listing of synonymy and explanation of the taxonomic history of this genus, see Jansonius and Hills (1976, card 3102; 1987, card 4564).

Remarks and comparisons.Tuberculatosporites Imgrund ex Potonié & Kremp 1954 encompasses monolete spores with a sculpture of coni, spinae or verrucae, spaced apart by areas of laevigate exine at least was wide as the sculptural elements.

Affinity. Polypodiophyta: Marattiaceae (Balme 1995).

Tuberculatosporites westbournensis McKellar & Cooling sp. nov.

Plate 11, figs 32–34; Plate 12, figs 1–6; Supplemental Plate 18, figs 9–11

Synonymy.

2002b  Tuberculatosporites westbournensis McKellar, ‘in press’*; Sajjadi & Playford, 117–118; pl. 3, figs 7–8.

2009 Tuberculatosporites westbournensis McKellar, ‘in press’*; Mantle, 37; pl. 4, fig. 15.

1998 Tuberculatosporites westbournensis McKellar*, 253–254; pl. 37, figs 11–16.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002b; Mantle 2009; both listed above); see explanatory note in Introduction].

Diagnosis. Spores monolete, bilateral. Amb elliptical; plano-convex to weakly concavo-convex in lateral (polar) aspect. Laesura straight, simple; 0.5–0.8 length of major equatorial axis. Exine <1–1.5 μm thick, sculptured variably with grana-verrucae and small conate-baculate elements spaced up to 1.5 μm apart. Grana-verrucae 0.5–3 μm high, subcircular to rounded-elongate in basal outline (0.5–3.5 μm in maximum diameter); coni-bacula 1–3 μm high, <1–2 μm in basal diameter. Sculpture may also include short rugulae (ca. 0.5 μm in height and width). Proximal sculpture generally reduced.

Dimensions. Equatorial diameter (28 specimens) length 20 (31) 36 μm; breadth 12 (19) 25 μm (McKellar 1998). Equatorial diameter (85 specimens) length 20.5 (33) 48 μm; breadth 12.5 (24) 33.5 μm (this study).

Holotype. Slide B351/2; R34/0; Q676; Plate 12, Figs 1–3.

Type locality. GSQ DRD 25, 78.74 m, Westbourne Formation.

Etymology. Named after the Westbourne Formation.

Remarks and comparisons.Tuberculatosporites sp. A, recorded by Burger (1980, 61, pl. 15, figs 14–15) from the Early Cretaceous of the Surat Basin, is differentiated by its predominantly baculate-spinulate sculpture. Polypodiidites horridus Backhouse 1988 (pp. 32–33, pl. 5, figs 1–3), from the latest Jurassic and Early Cretaceous of the Perth Basin (Western Australia), appears to be similarly, but more coarsely sculptured in individual specimens.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon, sometimes sporadic.

Previous records. Middle to Late Jurassic of Australia (McKellar 1998; Sajjadi and Playford 2002b; Mantle 2009).

Suprasubturma PERINOMONOLITES Erdtman 1947

Genus Aratrisporites Leschik emend. Playford & Dettmann 1965 

Type. Aratrisporites parvispinosus Leschik 1955; original designation.

Synonymy. See Playford and Dettmann (1965, 151).

Remarks and comparisons. The genus Aratrisporites Leschik emend. Playford & Dettmann 1965 encompasses two-layered, cavate, monolete spores with a loosely enveloping outer layer and a sculpture that includes coni and spinae.

Affinity. Isoetopsida (Pigg 1992; Balme 1995; Villanueva-Amadoz et al. 2014).

Aratrisporites woodii Cooling sp. nov.

Plate 12, figs 7–17; Supplemental Plate 18, figs 17–24

Diagnosis. Monolete spores, two-layered exine. Amb elliptical; plano-convex to weakly concavo-convex in lateral view. Laesura distinct to indistinct, straight, extending full length of spore; sinuous membranous lips comprise elevated (1.5–4 µm high) extensions of the proximal exoexine. Exine two-layered, thin (≤1 µm thick), with laevigate intexine proximally attached to, but distally and equatorially separated from, a sculptured exoexine (≤0.5 µm thick); layers distally and equatorially 1.5–7.5 µm apart. Exoexine sculptured with spinae (1–6 µm high, <0.5 µm wide basally, 1.5–8 µm apart); remainder of exoexine laevigate or finely rugulate/wrinkled.

Dimensions. Total length (21 specimens): 27 (35) 56 µm. Total breadth (21 specimens): 21.5 (26) 38.5 µm. Intexine length (21 specimens): 18 (24.5) 46 µm. Intexine breadth (21 specimens): 14.5 (19) 31.5 µm.

Holotype. Slide S16728 K GSQ DRD 26 214'2’ (1), G38/1; Plate 12, Figs 11, 12.

Etymology. JJC: After Geoff Wood, retired Manager of Stratigraphic Services, Santos Ltd, Adelaide.

Type locality. GSQ DRD 26, 66 m, Orallo Formation.

Remarks and comparisons. Because of the thinness of the exoexine and the fineness of the spinae, the sculptural elements on Aratrisporites woodii sp. nov. are frequently damaged, being represented by snapped spinae, and its exoexine often torn. This delicacy makes it more likely that these spores are in-situ rather than reworked. That other spores recorded herein as Aratrisporites spp. are likely to have been reworked is suggested by their much darker colour and more robust exoexine. Furthermore, there are other records of in-situ Aratrisporites spores from Cretaceous strata (e.g. Mohr et al. 2002; Kujau et al. 2013). The possibility that A. woodii is reworked cannot be entirely ruled out. Aratrisporites woodii is most closely comparable to A. paenulatus Playford & Dettmann 1965 but differs in having a finer exoexine and thinner and higher spinae. The spinae of A. paenulatus are 1–2 μm wide basally and 2–3 μm high, compared to those of A. woodii which are <0.5 μm wide basally and 1–6 μm high.

Occurrences (Cooling2020 ). Upper Westbourne Formation – Orallo Formation; rare and sporadic.

Turma HILATES Dettmann 1963 

Genus Aequitriradites Delcourt & Sprumont emend. Cookson & Dettmann 1961

Synonymy. See Delcourt et al. (1963, 290) or Dettmann (1963, 91).

Type.Aequitriradites dubius Delcourt & Sprumont emend. Delcourt, Dettmann & Hughes 1963; original designation.

Affinity. Hepaticae (Dettmann 1963, 1986).

Aequitriradites inornatus Backhouse 1988 

Plate 12, figs 18–20; Supplemental Plate 18, figs 29–31

Synonymy.

1988 Aequitriradites inornamentus Backhouse, 52–53 (text), and referred to as Aequitriradites inornatus Backhouse, 128 (in associated plate explanations for) pl. 1, figs 7–10.

1998 Aequitriradites inornatus Backhouse; McKellar*, 256–257.

1998 Aequitriradites sp. cf. A. inornatus Backhouse; McKellar*, 257; pl. 83, fig. 8.

*Unpublished PhD thesis.

Description. Zonate, distally hilate spores. Amb subcircular to subtriangular with convex sides and broadly rounded apices. Exine ca. 2–4 μm thick, rarely visible due to dark zona 8–16 μm wide equatorially. Distally sculpted with closely packed verrucae (1–4 μm high, 1.5–5 μm wide) with circular to subpolygonal bases; distal sculpture extends in a reduced form onto the distal surface of the zona. At the distal pole, the exine is partially to fully subdivided into polygonal to subpolygonal platelets, 2–7 μm in diameter, sometimes with one or more being partially detached or lost, forming a hilum 15–25 μm in maximum diameter. Proximal surface finely scabrate. Tetrad mark absent but for the presence of low radial ridges at the apices on some specimens.

Dimensions. Total equatorial diameter (11 specimens): 55 (70) 100.5 μm. Inner equatorial diameter (11 specimens): 42.5 (49) 61 µm.

Remarks and comparisons. McKellar (1998), in an unpublished PhD thesis and in an unpublished Geological Survey of Queensland manuscript (widely cited as ‘McKellar, in press’; see note in Introduction) ascertained, in personal communication with the species’ author, Dr John Backhouse, that, of the two orthographic variants mistakenly used for the specific name of this species in the originating publication (as outlined above in the synonymy), inornatus was the one that was intended. McKellar, citing Article 61 of the International Code of Botanical Nomenclature (Greuter 1994), adopted the latter epithet and noted also that it conforms with Latin usage (inornātus-a-um, unadorned, unornamented), unlike inornamentus. The correct citation of Aequitriradites inornatus Backhouse is here validated.

The zona of A. inornatus is characteristically darker than that of comparable species of Aequitriradites.

Occurrences (Cooling2020 ). Gubberamunda Sandstone – lower Mooga Sandstone; rare and sporadic.

Previous records. Early Cretaceous of Western Australia (Backhouse 1988), Westbourne Formation of Surat Basin (McKellar 1998).

Genus Januasporites Pocock emend. Singh 1964 

Synonymy.

1962 Januasporites Pocock, 6.

1964 Januasporites Pocock emend. Singh, 94.

Type.Januasporites reticularis Pocock 1962; original designation.

Januasporites spinosireticulatus McKellar & Cooling sp. nov.

Plate 12, Figs 21–25; Plate 13, Figs 1–4, 6–8; Supplemental Plate 19, Figs 14–17

Synonymy.

1998 Januasporites spinosireticulatus McKellar*, 258–257; pl. 38, figs 9–17.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

Diagnosis. Spores alete. Amb convexly subtriangular, subcircular to oval. Exine two-layered. Intexine laevigate, 1–2.5 μm thick. Exoexine thin, membranous, closely attached to, or slightly separated from, intexine; subreticulate-reticulate overall and bearing spinae, coni, bacula or subbaculate elements at points of intersection of muri. Sculpture ± uniformly developed or reduced on one surface (proximal?) where projections may be absent or small and imperceptibly developed. Muri ca. 0.5 μm in width and height; lumina subpolygonal, elongate to irregular, 1–8.5 μm in maximum diameter; proximal(?) reticulum usually more finely meshed than distal(?). Sculptural projections hyaline, <1–5.5 μm high, <1–3 μm in basal diameter. Exine commonly with an indistinct to infrequently distinct, subcircular, subrectangular to irregular opening or area of thinning (ca. 19–35 μm in diameter; usually represented only by a lighter coloured area) located on one surface (distal?).

Dimensions. Equatorial diameter (47 specimens) 29 (45) 59 μm (excluding sculpture) [McKellar 1998]. Equatorial diameter (60 specimens): 24 (44.5) 66 μm (this study).

Holotype. Slide S9764, K53/0; Q690; Plate 13, Figs 1–3.

Type locality. GSQ DRD 25, 90.80 m, Westbourne Formation.

Etymology. Named in description of its exoexinal sculpture.

Remarks and comparisons. The location of the exinal opening or area of thinning appears to be distal, but this is uncertain. In rare specimens, it is well defined and penetrates both layers. However, in the majority of cases, it is indistinct, and this may be a reflection of its confinement, in these individuals, to the intexinal layer. A similar feature occurs distally in J. spiniferus Singh 1964 and J. reticularis Pocock 1962, but the former is non-reticulate and often shows the rudiments of a faint, non-functional tetrad scar, and the latter lacks sculptural projections (spinae, coni, etc.) and is coarsely reticulate distally.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Late Jurassic of Queensland (McKellar 1998; Sajjadi and Playford 2002b).

Pollen

Anteturma VARIEGERMINANTES Potonié 1970 

Turma SACCITES Erdtman 1947

Subturma MONOSACCITES Chitaley emend. Potonié & Kremp 1954 

Infraturma PROSACCITES Maheshwari 1974 

Genus Callialasporites Sukh Dev emend. Maheshwari 1974 

(see Supplemental Appendix for type species and other details)

Callialasporites segmentatus (Balme) McKellar & Cooling comb. nov.

Supplemental Plate 19, figs 23, 24

Synonymy.

1957 Zonalapollenites segmentatus Balme, 33; pl. 9, figs 93–94.

1963 Callialasporites segmentatus (Balme) Srivastava*, 1323, fig. 3.

2002b  Callialasporites segmentatus (Balme) McKellar**; Sajjadi & Playford, pp, 123–124; pl.4, fig. 16; pl. 5, fig. 4.

2007 Callialasporites segmentatus (Balme) McKellar**; Ribecai, 7, 9, 11; pl. 1, fig.10.

1998 Callialasporites segmentatus (Balme) McKellar**, 265–266; pl. 39, figs 9–10.

See Sajjadi and Playford (2002b, 123) for additional synonymy.

*New combination invalid in Srivastava (1963), as no reference given to basionym [Article 33.2, International Code of Nomenclature for Algae, Fungi, and Plants (Turland et al. 2018)].

**New combination validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript [cited by others as McKellar, ‘in press’ (e.g. Sajjadi and Playford 2002b; Ribecai 2007); see explanatory note in Introduction].

Description. Monosaccate pollen grains. Amb circular to subcircular but distorted by intense convolute folding of the exoexine; generally indistinct corpus equatorial outline broadly parallel to amb. Exine two-layered with thin (ca. 0.5 μm thick), laevigate intexine and laevigate to scabrate exoexine of similar thickness. Two layers closely adpressed in polar regions but detached equatorially forming a narrow prosaccus (2–5 μm thick) with a convolute margin. Exoexine over corpus heavily convolutely folded producing a wrinkled appearance. A vestigial tetrad mark rarely faintly apparent. Ratio of corpus to total diameter 0.8–<1.

Dimensions. Total equatorial diameter (31 specimens): 36.5 (54) 73.5 μm.

Remarks and comparisons. The crenulate margin of Callialasporites segmentatus best serves to distinguish it from the other species of Callialasporites in this study.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Early Jurassic to Early Cretaceous of Australia (Balme 1957; de Jersey 1959; de Jersey 1963; Balme 1964; de Jersey and Paten 1964; Hill et al. 1966; Paten 1967; de Jersey 1971a; McKellar 1974; Backhouse 1975; Filatoff 1975; McKellar 1975; McKellar 1977; McKellar 1979; Morgan 1980; McKellar 1981c; McKellar 1981d; McKellar 1981a; Backhouse 1988; Burger 1989; Burger 1996; McKellar 1998; Sajjadi and Playford 2002b; Mantle 2009); Early Jurassic of South Victoria Land, Antarctica (Ribecai 2007).

Callialasporites propinquivelleris McKellar & Cooling sp. nov.

Plate 13, figs 5, 9–20; Supplemental Plate 20, figs 2–5

Synonymy.

1969 Araucariacites fissus Reiser & Williams (pars), 17, pl. 5, fig. 11 (non figs 12–17).

1998 Callialasporites propinquivelleris McKellar*, 267–269; pl. 39, figs 11–17; pl. 40, figs 1–2.

2004 Callialasporites propinquivelleris**; Cooper, 94, fig. 9.3.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, ‘in press’; see explanatory note in Introduction).

**Referring to C. propinquivelleris in McKellar (1998; unpublished PhD thesis) [Ian Raine, personal communication, February 2013; the compiler of figure 9.3 in Cooper (2004)].

Diagnosis. Pollen grains subcircular, infrequently oval to subquadrangular in equatorial outline. Tetrad mark rarely present, non-functional, faintly developed. Exine indistinctly two-layered. Intexine <1 μm thick, closely adpressed to thicker (1.5–2.5 μm) exoexine, usually not separately distinguishable (acavate). Exoexine punctate (corrosion), scabrate or generally with low, indistinct, ±subreticulate grana-verruca-rugula-like elements (usually coarser distally). Distal hemisphere commonly bisected by a longitudinal unstructured/unsculptured, usually lighter-coloured, thinner area of exine (leptoma); up to 5 μm wide, often bordered by folds.

Dimensions. Equatorial diameter (61 specimens) 41 (50) 61 μm (McKellar 1998). Total equatorial diameter (9 specimens): 36 (46.5) 53.5 μm (this study).

Holotype. Slide A274/1; V50/2; Q701; Plate 13, Figs 9, 10.

Type locality. GSQ DRD 24, 325.55 m, upper Evergreen Formation.

Etymology. Latin: propinquus-a-um, near, neighbouring, closely connected; vellus-ĕris (n), coat, hide, fleece; together referring to the overall close adpression of the exinal layers.

Remarks and comparisons.Callialasporites propinquivelleris sp. nov. is a generally nondescript species displaying moderate variation in the character of its exoexinal surface. It incorporates pollen previously referred to as Zonalapollenites sp. cf. Z. segmentatus Balme 1957 (McKellar 1978a–e, etc.), and is closely comparable with forms designated by Filatoff (1975, 82–83, 111; pl. 24, figs 1a–b) as Callialasporites sp. cf. C. segmentatus (Balme).

Chasmatosporites canadensis Pocock (1970, 111, pl. 26, figs 35–36) and C. stelckii Pocock (1970, pl. 26, fig. 37), respectively from the Middle and Middle – Late Jurassic of western Canada, are also closely comparable with Callialasporites propinquivelleris. However, Chasmatosporites stelckii has a thinner exoexine; and the exoexinal surface, in both this species and C. canadensis, is smooth to scabrate (lacking the low grana-verruca-rugula-like sculpture of the present species, as well as the occasional development of a non-functional tetrad mark). Additionally, in both of the Canadian species, the leptoma extends only about two-thirds of the equatorial diameter, contrasting with the present species, in which the thinner region of exine (when discernible) totally bisects the distal hemisphere. Certain pollen from the Albian of Canada (Cycadopitys sp. B; Hopkins 1974, 21; pl. 5; fig. 64) also appear to be similar to Callialasporites propinquivelleris.

The species is differentiated from C. segmentatus, with which it is morphologically intergradational, by the absence of both prominent exoexinal vesiculation (=convolute folding of Filatoff 1975, 81–83) and the associated development of a characteristically irregular equatorial outline. Moreover, as indicated above, some equatorial separation of the exinal layers occurs in C. segmentatus (ratio corpus/total diameter: 0.80–almost 1.0), as in C. microvelatus (0.80–0.90).

Araucariacites fissus Reiser & Williams is generally larger [equatorial diameter 53–120 μm, this publication; compare Reiser and Williams 1969 (see footnote to synonymy above)] and has a less rigid (thinner), apparently single-layered(?) exine prone to equatorial splitting. The possibility of a close relationship between the present species and A. australis Cookson ex Couper 1953 requires further investigation. Filatoff (1975) has suggested that his Callialasporites sp. cf. C. segmentatus may represent an intermediate between Balme’s C. segmentatus and Cookson’s species (considered by him to be two-layered).

In New Zealand, C. propinquivelleris first appears in late Aratauran (Sinemurian) strata. Thus, it predates C. dampieri, C. minus, C. segmentatus and C. trilobatus, all of which appear in the early Ururoan (Pliensbachian) (pers. comm. with JLMcK, also cited in McKellar (1998) as de Jersey and others (in preparation); not referenced here as unpublished).

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare and sporadic.

Previous records. Late Jurassic of Queensland (McKellar 1998).

Turma ALETES Ibrahim 1933 

Subturma AZONALETES Luber emend. Potonié & Kremp 1954 

Infraturma PSILONAPITI Erdtman 1947

Genus Peroaletes Bharadwaj & Singh 1964 

(see Supplemental Appendix for type species and other details)

Peroaletes ieiunus McKellar & Cooling sp. nov.

Plate 13, figs 21–26; Plate 14, figs 1–5; Supplemental Plate 20, figs 27–29

Synonymy.

1998 Peroaletes ieiunus McKellar*, 288–289; pl. 42, figs 15–23.

*New species: Originally proposed in an unpublished PhD thesis (McKellar 1998); validly published here.

Diagnosis. Spores alete. Amb subcircular, subpolygonal, quadrangular or irregular. Sclerine imperceptibly two-layered. Inner layer 1.5–3 μm thick, with: (i) one hemisphere (distal?) generally characterised by a variably developed, simple to complex system of low, concentric, radial or irregularly distributed folds; otherwise irregularly and narrowly canaliculate in appearance (with compression); and (ii) other hemisphere (proximal?) laevigate, punctate-reticulate (corrosion), or rarely sculptured with grana-verrucae (height <1–3 μm; basal outline subcircular to rounded-elongate, 1–8.5 μm in maximum diameter) and/or apiculae (height 1–3 μm; basal diameter <1–1.5 μm); usually sparsely distributed and indistinct. Enveloping outer layer laevigate to very finely and sparsely granulate, thin, perine-like; closely attached to, and generally indistinguishable from, inner layer.

Dimensions. Equatorial diameter (85 specimens) 23 (43) 63 μm (McKellar 1998). Equatorial diameter (38 specimens) 27 (38) 61 μm (this study).

Holotype. Slide A1933/2, Q42/3; Q751; Plate 13, Figs 23–25.

Type locality. GSQ DRD 25, 74.95 m, Westbourne Formation.

Etymology. Latin: iēiūnus-a-um, insipid, poor, uninspiring; referring to the morphography of the species.

Remarks and comparisons. The presence of a perine-like layer in P. ieiunus sp. nov. is suggested only in rare specimens where partial detachment is apparent. Close comparison of the species can be made with the specimen figured by Filatoff (1975, pl. 8, fig. 10) as Pilasporites marcidus Balme, but the relationship with the original material of the latter species (Balme 1957, 28–29, pl. 6, figs 70–72) is less clear.

Spores of Equisetum laterale Phillips, described and figured by Gould (1968, 165; pl. 2; figs 3–13) from the Walloon Coal Measures (Clarence-Moreton Basin), although generally comparable with P. ieiunus, are distinguished by their scabrate to microrugulate sclerine. Peroaletes allenii Batten is differentiated by its normally present and readily identifiable perine-like layer and its smooth to scabrate inner layer, which lacks the complex system of folds or the ‘canaliculate’ appearance associated with the inner layer of P. ieiunus.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Late Jurassic of Queensland (McKellar 1998).

Algae

Order PTEROSPERMATALES Schiller 1925

Family TASMANITACEAE Sommer 1956 nom. corr. Tappan 1980 

Genus Maculatasporites Tiwari 1964

Type. Maculatasporites indicus Tiwari 1964; original designation.

Affinity. Following McKellar (1998), the association of the species described here, with the genus Maculatasporites Tiwari 1964, is regarded as only tentative. As such, their prasinophyte association (Tappan 1980) is also only tentative, though their algal origin is highly likely.

Maculatasporites fionabethiana McKellar sp. nov.

Plate 14, figs 6–15; Supplemental Plate 21, figs 22, 23

Synonymy.

1998 Maculatasporites fionabethiana McKellar*, 302–303; pl. 44, figs 7–9; pl. 45, figs 1–6.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, in press; see explanatory note in Introduction).

Diagnosis. Alete; biconvex, subcircular to oval in outline. Sclerine <1.5–3 μm thick (two-layered?), coarsely reticulate overall, often sparsely and finely granulate. Muri 1.5–4.5 μm high (sometimes higher equatorially), 1–3.5 μm in basal width, double-walled (hollow), generally sinuous and rope-like in appearance; crests narrowly rounded to infrequently flange-like. Lumina scabrate to finely rugose-reticulate; irregular, elongate to predominantly equidimensional (often subpolygonal) in outline, 3.5–16 μm in maximum diameter. Individuals occasionally fractured normal to equatorial plane.

Dimensions. Equatorial diameter (30 specimens) 67 (81) 100 μm (including sculpture) [McKellar 1998]. Equatorial diameter (15 specimens) 39.5 (64) 139 μm (including sculpture) [this study].

Holotype. Slide S9764, M30/0; Q783; Plate 14, Figs 6, 7, 8.

Type locality. GSQ DRD 25, 90.80 m, Westbourne Formation.

Etymology. JLMcK: After my eldest daughter, Fiona Elizabeth McKellar.

Remarks and comparisons.Maculatasporites fionabethiana sp. nov. is a distinctive species, being readily differentiated from previously published species of the genus by its sinuous, double-walled muri, which commonly assume a rope-like appearance.

Occurrences (Cooling2020 ). Upper Westbourne Formation – lower Mooga Sandstone; rare to uncommon.

Previous records. Late Jurassic of Queensland (McKellar 1998).

Maculatasporites eurombahensis McKellar & Cooling sp. nov.

Plate 14, figs 16–21 

Synonymy.

1998 Maculatasporites eurombahensis McKellar*, 301–302; pl. 44, figs 1–6.

*New species: Validly published here. Originally proposed in an unpublished PhD thesis (McKellar 1998) and in an associated unpublished Geological Survey of Queensland manuscript (cited by others as McKellar, in press; see explanatory note in Introduction).

Diagnosis. Alete; ±subcircular in outline. Sclerine <1–2 μm thick, appearing two-layered in rare specimens; one hemisphere (distal?) regularly reticulate to poorly subreticulate. Sculpture comprehensively developed on distal(?) surface or reduced to absent in equatorial/subequatorial regions; muri <1–2 μm in height and basal width, with mural elements in coarsely sculptured specimens appearing hollow; lumina (where enclosed) polygonal to irregular (variable from specimen to specimen), 2–9 μm in maximum diameter. Opposite hemisphere (proximal?) laevigate, scabrate, finely granulate, granulate-rugulate or finely subreticulate. Individuals often fractured normal to equatorial plane.

Dimensions. Equatorial diameter (37 specimens) 40 (59) 79 μm. McKellar 1998.

Holotype. Slide S8866, V23/0; Q777; Plate 14, Fig. 16.

Type locality. GSQ DRD 22, 134.01 m, Hutton Sandstone.

Etymology. Named after Eurombah Creek and Eurombah Dome, north of Roma, where outcropping strata of the lower Walloon Coal Measures were previously recognised as the Eurombah Formation.

Remarks and comparisons. Specimens with a poorly subreticulate, almost rugulate distal(?) sculpture are generally those where the sculpture is restricted to the central area of the surface (Fig. 53F). Maculatasporites fionabethiana sp. nov. (above) is distinguished by its coarser reticulum, which is developed on both spore surfaces.

Previous records. Late Jurassic of Queensland (McKellar 1998).

Palynofloral assemblages from the lower sections of all three stratigraphic boreholes are assignable to the informally defined ‘Retitriletes watherooensis association zone’ of McKellar [1998; see discussions in ‘Introduction’ and ‘Results’, the latter (Section 4) providing McKellar’s unpublished definition of this biostratigraphic unit]. It was derived by modification of the Retitriletes watherooensis Zone of Backhouse (1978) and the Retitriletes watherooensis Oppel Zone of Helby et al. (1987). The lower limit of the zone, as defined by McKellar, in the Surat Basin succession, was identified by him as occurring below the middle of the Westbourne Formation; this lower zonal boundary was not encountered in the present study. The overlying assemblages are all assignable to the Ruffordiaspora australiensis Interval Zone of Helby et al. (1987). The boundary between these two zones is tightly constrained in GSQ Roma 2, falling between 158.37 and 158.6 m, approximately a third of the way down the formation in this borehole. The boundary in GSQ DRD 26 is also reasonably well constrained falling between 212.37 and 215.9 m, five meters above the base of the Gubberamunda Sandstone. Due to the overall coarser-grained character of the Gubberamunda Sandstone in GSQ Dalby 1, relatively few palynological samples were taken. As a result, the zonal boundary is less well constrained in GSQ Dalby 1 than in the other two boreholes, falling somewhere between 145.09 and 179.39 m, closer towards the middle of the Gubberamunda Sandstone. The anomalously low stratigraphic occurrence of the boundary between the two zones in GSQ DRD 26 relative to the other two boreholes may be in part due to differential compaction. The Gubberamunda Sandstone in GSQ DRD 26 contains a higher proportion of siltstone compared to the other two boreholes. Alternatively, there may be some unidentified disconformity in the GSQ DRD 26 succession from non-deposition or erosion of strata equivalent to the lower part of the Gubberamunda Sandstone recorded in GSQ Roma 2 and GSQ Dalby 1. The view that hiatus exists at the Westbourne Formation–Gubberamunda Sandstone boundary in GSQ DRD 26 (here representing the northwestern Surat Basin) is tentatively supported by the suggestion that hiatus exits at the equivalent Westbourne Formation–Hooray Sandstone boundary in some areas of the immediately adjacent Eromanga Basin (Green 1997). Given the proportionally small amount of potentially missing section, just under 100 m in GSQ Roma 2, in the centre of the basin, and somewhere between 13 and 47 m in GSQ Dalby 1, the cryptic nature of a possible disconformity is not unexpected.

The palynofloral assemblages recorded here, particularly from GSQ Roma 2, appear to offer a complete record of terrestrial deposition across the Jurassic–Cretaceous transition. Covering an interval from the mid-Tithonian to the early Hauterivian, based on a combination of palynostratigraphic and geochronological dating (Cooling et al. 2021), this part of the Surat Basin succession is comparable to equivalent sections from a number of other Australian basins. The adjoining Clarence-Moreton Basin, to the east and southeast (for the NSW section, not for the truncated section in Queensland), and the adjoining Eromanga Basin, to the west, both include strata of potentially equivalent age. Thus, with further work therein, comparison of them with the record published here may assist in improving interpretation of the stratigraphy of those basins. To date, the Grafton Formation in the Clarence-Moreton Basin in New South Wales has yielded only a badly weathered palynoflora taken from surface samples, the age of which could not be reliably constrained beyond assignment of a probable Late Jurassic and/or Early Cretaceous age (Burger 1994). On the other hand, the stratigraphy of the Jurassic–Cretaceous transition in the Eromanga Basin is complex and beset by uncertainty (Cook et al. 2013, fig. 7.2). Numerous palynological investigations have been undertaken on different elements of the stratigraphy of the Eromanga basin (e.g. Burger 1989; Shield 1991; McKillop 2002; Sajjadi and Playford 2002a, 2022b), revealing several possible unconformities that have hindered the development of a complete picture. In the Maryborough Basin, located to the northeast of the Surat Basin, the Grahams Creek Formation is a primarily volcaniclastic unit that is considered to be of latest Jurassic to Early Cretaceous age based on a number of K-Ar dates (Green and Webb 1974; Cranfield and Murray 1989; Kendall 1992; Cranfield 1993). No palynological study has been carried out on this formation, but it contains siltstones and carbonaceous mudstones that could prove to be palynologically productive, and plant macrofossils are known to occur in the unit (Cranfield 1993).

The palynofloral assemblages described in this study were deposited in a terrestrial setting with only rare occurrences of Micrhystridium in the lower part of the succession (Westbourne Formation, Gubberamunda Sandstone and basal Orallo Formation). This acritarch genus is known from most of the Jurassic Surat Basin succession, and its environmental significance, along with the significance of dinoflagellate cysts reported from the Walloon Coal Measures and Precipice Sandstone, have been widely debated (Reiser and Williams 1969; McKellar 1974; McKellar 1998; Bianchi et al. 2018; Martin et al. 2018; Wainman et al. 2019). These records show that there appears to have been spikes in the abundance of the spinose acritarchs and dinoflagellate cysts during the deposition of the Precipice Sandstone, Evergreen Formation and Walloon Coal Measures, especially in the Boxvale Sandstone Member and overlying Westgrove Ironstone Member of the upper Evergreen Formation (deposited during the Toarcian peak in eustatic sea level; e.g. Bradshaw and Yeung 1992; McKellar 1998).

Spinose acritarchs and dinoflagellate cysts are most frequently associated with marine or brackish waters and their presence in the Surat Basin does seem to indicate some form of connection between the Surat Basin and the marine realm, albeit a distant one. However, Wainman et al. (2019) have suggested that dinoflagellate cysts recovered from the Walloon Coal Measures may have been produced by a freshwater dinoflagellate population that could have survived by adaptation from marine ancestors introduced to the basin in an earlier marine transgression. The complete disappearance of Micrhystridium from samples recovered from the upper Orallo Formation and lower Mooga Sandstone (Burger 1974, this publication) seems to indicate that, during the time of deposition of these units, the Surat Basin was more separated from the marine realm then previously, perhaps contingent on a low in eustatic sea level at that time. This interval in the succession has been considered to be of Valanginian to early Hauterivian age (Cooling et al. 2021), which approximately coincides with global sea levels reaching their nadir during the Valanginian (Haq 2014).

While the link between palynofloral and macrofloral abundances is not a direct one, being influenced by sedimentologic and taphonomic effects, some broad conclusions about the parent flora can be made for the Surat Basin. It appears that, during the mid-Tithonian to early Hauterivian, it was dominated by ferns, conifers and lycopods, with bryophytes, seed ferns, and some component of ginkgoes, cycads and/or gnetales also present. The majority of the samples from this project, with their high proportion of fern spores to conifer pollen, can be recognised as coming from a backswamp or floodplain facies, as defined by Pelzer et al. (1984). This paleoenvironmental interpretation supports the view that the Westbourne Formation to Mooga Sandstone interval was, like much of the Australian Late Jurassic succession, deposited in a highly fluvial environment with meandering and braided streams, shallow lakes, and swampy floodplains (Exon 1976; Bradshaw and Yeung 1992; Green 1997; Cook et al. 2013).

Herein is presented a detailed record of the taxonomy and occurrences of the palynomorphs recovered from the upper Westbourne Formation, Gubberamunda Sandstone, Orallo Formation and lower Mooga Sandstone in the Queensland portion of the Surat Basin. The palynofloras are diverse and well preserved, with 212 individual taxa being identified. With the exception of a possible small disconformity near the base of the Gubberamunda Sandstone in GSQ DRD 26, the studied interval appears to provide a complete record of deposition (in Queensland) from the mid-Tithonian to the early Hauterivian. The present work completes the overall undertaking of documenting the palynofloral assemblages of the Surat Basin succession by bridging the gap between the works of McKellar (1998) and Burger (1974, 1980).

The lead author would like to express her deep gratitude to Dr John Filatoff, Dr Dan Mantle, Professor Jen O’Keefe and Professor Joan Esterle. Dr Filatoff, Dr Dan Mantle and Professor O’Keefe for their careful and thoughtful reviews of the systematic palynology section of the thesis that this publication was prepared from (apart from insertion of the previously unpublished taxonomy of JLMcK), and Professor Esterle for her advice and feedback on all non-palynological components of this manuscript, and the larger PhD. Thanks are also owed to Geoff Wood (previously of Santos Ltd) and Santos’ Stratigraphic Services team, for the production of the slides used in this study. Also to the School of the Environment (UQ), the Centre for Natural Gas (UQ), and the Geological Survey of Queensland, for their initial support for this study and their continued, although interrupted, supply of the Olympus microscope and camera used throughout it.

No potential conflict of interest was reported by the author(s).