Abstract The Carboniferous Foraminifera are composed of representatives of three classes: Fusulinata, Miliolata and Nodosariata. Despite ample literature on Paleozoic Allogromiata and Textulariata, the real presence of these classes remains questionable during the Carboniferous and they are thus excluded herein. The main biostratigraphical markers belong to the superfamilies Archaediscoidea, Lasiodiscoidea and Bradyinoidea, even if many genera among the archaediscoids still have a controversial nomenclature, as well as do some lasiodiscids and bradyinoids. Secondary biostratigraphical markers belong to Lituotubelloidea (= ‘Tournayelloidea’ of the authors), Endothyroidea and Loeblichioidea (these latter giving rise to the primitive Fusulinida). The Miliolata appear at the Visean/Serpukhovian boundary interval. The typical Carboniferous miliolates are primitive nubeculariins and cornuspirinins. Tubiphytids might be miliolate and cyanobacterium consortia, derived from the nubeculariin Palaeonubecularia . The most primitive nodosariates (syzraniids) appeared in the Moscovian; and gave rise, in the latest Carboniferous, to Protonodosaria , Nodosinelloides and possibly Polarisella , Paravervilleina and the oldest Geinitzinoidea. Palaeobiological data are mainly provided by the genera Bradyina , Tetrataxis and Climacammina . Palaeobiogeographical distributions of Pojarkovella , Janischewskina, Eosigmoilina , Brenckleina , Spireitlina , Hemigordius and Syzrania testify to the successive foraminiferal migrations between the Palaeotethys, Ural and Panthalassan oceans. Two taxa are created: Eoparastaffellidae and Banffellinae.

Abstract: This review has been undertaken in order to present some interpretations about the biostratigraphy of the smaller foraminifers belonging to four classes present during the Permian: Fusulinata, Miliolata, Nodosariata and Textulariata. Biostratigraphic markers of these classes are principally known in the orders and superfamilies of Lasiodiscoidea, Bradyinoidea and Globivalvulinoidea (Fusulinata), Cornuspirida (Miliolata), and in the entire class Nodosariata. The class Textulariata is too little known during the Permian to play a significant biostratigraphical role: nevertheless, the appearance of the order Verneulinida is probably an important bioevent. The main genera among the lasiodiscids are Mesolasiodiscus , Lasiodiscus , Lasiotrochus , Asselodiscus , Pseudovidalina , Xingshandiscus and Altineria ; the bradyinoids Bradyina and Postendothyra ; the globivalvulinoids Globivalvulina , Septoglobivalvulina , Labioglobivalvulina , Paraglobivalvulina , Sengoerina , Dagmarita , Danielita , Louisettita , Paradagmarita , Paradagmaritopsis and Paremiratella ; the miliolates Rectogordius , Okimuraites , Neodiscus , Multidiscus , Hemigordiopsis , Lysites , Shanita and Glomomidiellopsis , and the tubiphytids and ellesmerellids, which might be specialized miliolate and cyanobacterium consortia, with reference to microstructures and phylogenies of these groups. The Nodosariata markers belong to Nodosinelloides , Tezaquina , Polarisella , Geinitzina , Pachyphloia , Rectoglandulina , first true Nodosaria , Langella , Pseudolangella , Calvezina , Cryptoseptida , Cylindrocolaniella , Colaniella , Frondina and Ichthyofrondina , but their lineages are too poorly understood to permit an accurate biostratigraphic use at the present time. The superfamily Geinitzinoidea is emended. Finally, palaeobiogeographical implications based on Shanita , Colaniella and Altineria are given.

Abstract As important components of extinct as well as modern reefs, the measurement of changes in the composition of reef biota is crucial in order to evaluate the influence of extrinsic factors on the marine communities. The dramatic abiotic changes in the eastern and northern Pangea was mirrored by a gradual transition from a photozoan to a heterozoan association and the appearance of cool- (temperate-) water carbonates both in reef and carbonate ramp environments. Analyses of large skeletal and microbiotic components as well as microfacies succession were used for detailed explanation of reef structure, especially for lesser-known heterozoan skeletal mounds. The youngest skeletal mounds are recognized in the Roadian. The stable isotope data demonstrated a negative oxygen shift between latest Sakmarian and late early Artinskian coinciding with the end of P2 glaciation. The multiplicative nature of the event included the series of successive changes of extrinsic factors such as ice melting in interglacial episodes, eustatic ocean level rise, change of oceanic circulation and decrease of water temperature. The late Artinskian and subsequent Kungurian climatic impacts in the Northern Hemisphere were irreversible for the photozoan biota and prevented its further development. Roadian (Guadalupian) bryonoderm extended skeletal mounds developed in rather warm-water environments.

Abstract One unresolved conceptual problem in some Palaeozoic sedimentary strata is the boundary between the concepts of “shell concentration” and “reef”. In fact, numerous bioclastic strata are transitional coquina–reef deposits, because either distinct frame-building skeletons are not commonly preserved in growth position, or skeletal remains are episodically encrusted by “stabilizer” (reef-like) organisms, such as calcareous and problematic algae, encrusting microbes, bryozoans, foraminifers and sponges. The term “parabiostrome”, coined by Kershaw, can be used to describe some stratiform bioclastic deposits formed through the growth and destruction, by fair-weather wave and storm wave action, of meadows and carpets bearing frame-building (archaeocyaths, bryozoans, corals, stromatoporoids, etc.) and/or epibenthic, non-frame-building (e.g. pelmatozoan echinoderms, spiculate sponges and many brachiopods) organisms. This paper documents six Palaeozoic examples of stabilized coquinas leading to (pseudo)reef frameworks. Some of them formed by storm processes (generating reef soles, aborted reefs or being part of mounds) on ramps and shelves and were consolidated by either encrusting organisms or early diagenesic processes, whereas others, bioclastic-dominated shoals in barrier shelves, were episodically stabilized by encrusting organisms, indicating distinct episodes in which shoals ceased their lateral migration.

Abstract Shelled phosphorites of Early Cambrian age are common in the Avène-Mendic autochthonous unit (Marcory Formation) and the Mélagues nappe ( “Heraultia beds” of the Lastours Formation), northern Montagne Noire (France). Palaeogeographically, the concentration of phosphate took place along the shelf edge between a stable inner platform (southern Montagne Noire) and an unstable slope-to-basin sea floor preserved in the northern Montagne Noire. Petrography, back-scattered SEM (scanning election microscopy) and elemental mapping by EDS (energy dispersive system) show that the phosphorites were generated by repeated alternations of low sedimentation rates and condensation forming hardgrounds, in situ early diagenetic phosphogenesis, winnowing and polyphase reworking of previously phosphatized skeletons and hardground-derived clasts. The succession of repeated cycles of sedimentation, phosphate concentration and reworking led to multi event phosphate deposits rich in allochthonous particles. Associated accumulations of exhumed and reworked pyrite clasts reflect final deposition in a mainly dysaerobic substrate.

Abstract All bioherms from the Early Cambrian (Botoman) Matoppa Formation of the Nebida Group in SW Sardinia were previously thought to be dominated by Epiphyton. However, at “La Sentinella” (Serra Scoris Hill), they are composed of Girvanella, Razumovskia, Botomaella and Renalcis, with Epiphyton and archaeocyaths as accessory components. This association forms two unusual types of crust boundstone, consisting of stacked flat or curved crusts and saucer-like archaeocyaths delimiting shelter cavities. Dendrolitic Renalcis archaeocyath–cement boundstone caps the bioherm. Analysis of the La Sentinella reef complex and comparison with similar constructions from Mongolia (Zuune Arts, Salaany Gol), Nevada (Stewart's Mill, Battle Mountain), Mexico (Sonora) and China (Tianheban Formation) suggest that episodic deposition of fine-grained siliciclastic or carbonate sediment followed by periods of non-deposition enabled the calcimicrobial rafts and crusts to colonize the substrate and then provide synoptic relief for the development of a dendrolitic Renalcis–cement framework. “La Sentinella” is one of the rare examples of Cambrian reef complex displaying community replacement, from an initial stage of thrombolitic and/or flat-stacked microbial crusts on a muddy substrate to an arched microbial crust system, to a more resistant Renalcis–cement boundstone. Such bioherms reflect an open-shelf, shallow-marine environment of increasing energy.

Abstract Exposures of the Botoman (Lower Cambrian), Lemdad and Issafen formations on the Lemdad syncline, southern High Atlas, provide an excellent example of the interactions between tectonic events, magmatic activity and carbonate productivity. The major factors that controlled the nucleation of carbonate factories on the Botoman High Atlas platform were: (i) synsedimentary tectonism, as normal faulting resulted in tilting of fault blocks causing irregular topographies and subsequent sharp erosion; (ii) volcanism, because pyroclastic influx smothered carbonate factories except in distal areas of the platform or during quiescent episodes of volcanic activity; and (iii) the influence of successive shoaling parasequences. The Botoman reefs exhibit a wide range of external morphologies, including tabular (biostromes) and domal (bioherms and patches) boundstones, which do not exceed 3.5 m of thickness. Although archaeocyathan–microbial reefs only developed under clear-water conditions, microbial reefs grew also under turbid-water conditions. Domal and digitate stromatoids, Girvanella crusts, Epiphyton bushes and thromboid–stromatoid intergrowths document the ability of some microbial communities to develop heterotrophic strategies when submitted to a moderate terrigenous input. Turbidity was a major ecological factor that constrained development of filter/suspension-feeder and phototrophic organisms, but not necessarily of benthic non-phototrophic microbial communities.

Abstract In the abandoned slate quarry of Guernanic, Gourin (Morbihan, France), a single horizon (Upper Member of the Schistes de Postolonnec Formation) has yielded an exquisitely preserved Llandeilian (Middle Ordovician) echinoderm assemblage composed of the ophiuroid Taeniaster armoricanus sp. nov. and the mitrate Mitrocystella incipiens. These two groups of echinoderms represent the first fossils formally described from the Middle Ordovician of the Gourin area. The brittlestar T. armoricanus sp. nov. is the third and oldest ophiuroid reported so far in the Palaeozoic of the Armorican Massif. The mitrate Mitrocystella is also described for the first time from western Brittany. Taphonomic features of this ophiuroid–stylophoran aggregation suggest that it probably corresponds to the rapid burial of a life assemblage in an otherwise quiet and moderately deep setting (shelf) below, but close to, storm wave base. This echinoderm association represents the oldest evidence for a gregarious mode of life for ophiuroids, as well as the oldest indisputable example of a mixed ophiuroid–stylophoran meadow.

Abstract Silurian reefs are well known to comprise frame-building corals, stromatoporoids and algae, but also a range of calcimicrobial components and micritic sediments of possible microbial origin. The margins of Wenlock patch reefs tend to have diffuse edges that grade into the surrounding bedded facies because of talus shed from the reefs. However, portions of patch reefs show sharp-bounded reef margins, with bedded limestones terminating abruptly against the reef edge. Examples of sharp boundaries where the reef comprises only carbonate mudstone–wackestone with poorly-defined gross fabric, and containing no metazoan framework, have been found in Wenlock patch reefs the UK and Gotland. Although in some cases the micrite may demonstrate a peloidal structure, in others there is no clear structure, broadly fitting the aphanitic (structureless) type of fabric found in leiolites (suspected microbial facies that show no structure). The fabrics are interpreted to have been formed by microbial mediation of micrite precipitation as part of reef construction, and are therefore automicrites. In all cases the sharp reef edges indicate coherence of the micritic fabric, interpreted as a lithified wall against which bedded limestones were deposited. This arrangement supports published interpretations of pronounced topography of Wenlock patch reefs, and shows the presence of steep, vertical and, possibly, overhanging reef margins, formed prior to bedded sediment accumulation. Thus, there is likely to have been a time interval between reef formation and deposition of bedded sediments, possibly caused by reef upward growth in transgressive settings, followed by catch-up of bedded limestone deposition.