Abstract: A new anurognathid pterosaur, Vesperopterylus lamadongensis gen. et sp. nov., is erected based on a complete skeleton with a skull preserved. It is characterized by two short distinct ridges present on the ventral surface of the cervical vertebrae; coracoids slightly longer than scapula; humerus, wing phalanx 3 and tibia nearly the same in length; grooves clearly present on the posterior surface of the wing phalanges 1–3; and the first toe reversed. It is the first anurognathid pterosaur from China with a definitively short tail, and the first pterosaur with a reversed first toe. The reversed first toe of Vesperopterylus indicates that it had arboreal habitats. The discovery of Vesperopterylus lamadongensis from the Jiufotang Formation strongly expands the geological age range for anurognathid pterosaurs. Supplementary material: The character list and data matrix for phylogenetic analysis are available at https://doi.org/10.6084/m9.figshare.c.3873394

Abstract: The Brazilian Crato Formation (Lower Cretaceous, Aptian) is well known for its rich pterosaur fauna. This paper deals with a new find represented by four articulated mid-cervical vertebrae. The vertebrae show a morphology consistent with that seen in the Chaoyangopteridae, especially the relative elongation, low neural spines, lack of pneumatic foramina on the lateral face of the centra and the presence of well-developed postexapophyses. Chaoyangopterids are, so far, represented with confidence only in Chinese deposits; the only record outside the Jehol Group is the Crato Formation form Lacusovagus magnificens , a partial skull whose assignment to the Chaoyangopteridae has been disputed. Given this controversy, we review the phylogenetic position of Lacusovagus , and discuss the nesting of our new specimen among theChaoyangopteridae, providing some comments concerning the composition of the group. We conclude that our new specimen provides further support for the presence of chaoyangopterids in the Early Cretaceous of Brazil. Supplementary material: Phylogenetic analysis data are available at: https://doi.org/10.6084/m9.figshare.c.3873391

Abstract Over the last 25 years, rich vertebrate assemblages have been discovered in three distinct formations of the Late Jurassic and Early Cretaceous of Thailand. This work aims to compare the taxonomic assemblages of SE Asia within their palaeogeographical context in Asia. Occurrences of 477 taxa in 94 Regional Faunal Assemblages (RFA) have provided the raw material for producing a dissimilarity matrix based on the Raup & Crick index. These distances have been investigated statistically to infer relationships between the diverse faunal assemblages in space and time. Our results show that the Thai formations are more similar to each other than to any other formations, suggesting a strong provincialism. The relationship of SE Asian RFAs with other Asian RFAs is more influenced by the presence of freshwater or near-shore taxa than by strictly terrestrial ones. Our analysis shows that the faunal interchange between RFAs was rather low from the Late Jurassic to the end of the Early Cretaceous. However, faunal dispersals dramatically decreased during the mid-Early Cretaceous in Asia. The faunas show an overall stronger provincialism during the mid-Early Cretaceous, indicating the role of possible geographical barriers. This event is characterized by the absence of ornithischian dinosaurs in the Sao Khua Formation although they are present in the under- and overlying formations. Taxonomic diversity and exchanges between faunal assemblages recovered rapidly as early as the Aptian in Asia, but the fauna of SE Asia still retained a strong biogeographical signature.

Abstract The turtle assemblages from the Khorat Group consist mainly of trionychoids. They include the primitive Trionychoidae Basilochelys and basal eucryptodiran turtles from the Phu Kradung Formation (?Late Jurassic); the adocid Isanemys srisuki , the carettochelyid Kizylkumemys sp. and undetermined Trionychoidea from the Sao Khua Formation (Early Cretaceous); and the carettochelyid Kizylkumemys khoratensis and the adocid Shachemys sp. from the Khok Kruat Formation (Aptian). Our study shows some faunal links between the turtle faunas from the Khorat Group and those from the peripheral regions of Asia during the time span of the Khorat Group. Thus the coastal regions of Asia, and more particularly SE Asia, may have been important places for the origin and early diversification of the trionychoids.

Abstract Assessing the quality of the fossil record is notoriously hard, and many recent attempts have used sampling proxies that can be questioned. For example, counts of geological formations and estimated outcrop areas might not be defensible as reliable sampling proxies: geological formations are units of enormously variable dimensions that depend on rock heterogeneity and fossil content (and so are not independent of the fossil record), and outcrop areas are not always proportional to rock exposure, probably a closer indicator of rock availability. It is shown that in many cases formation counts will always correlate with fossil counts, whatever the degree of sampling. It is not clear, in any case, that these proxies provide a good estimate of what is missing in the gap between the known fossil record and reality; rather they largely explore the gap between known and potential fossil records. Further, using simple, single numerical metrics to correct global-scale raw data, or to model sampling-driven patterns may be premature. There are perhaps four approaches to exploring the incompleteness of the fossil record, (1) regional-scale studies of geological completeness; (2) regional- or clade-scale studies of sampling completeness using comprehensive measures of sampling, such as numbers of localities or specimens or fossil quality; (3) phylogenetic and gap-counting methods; and (4) model-based approaches that compare sampling as one of several explanatory variables with measures of environmental change, singly and in combination. We suggest that palaeontologists, like other scientists, should accept that their data are patchy and incomplete, and use appropriate methods to deal with this issue in each analysis. All that matters is whether the data are adequate for a designated study or not. A single answer to the question of whether the fossil record is driven by macroevolution or megabias is unlikely ever to emerge because of temporal, geographical, and taxonomic variance in the data.