New reptiles from the Middle Triassic of Germany and the early evolutionary history of lepidosaurs

• Applicant: Professor Dr. Rainer Schoch
• Subject Area: Palaeontology
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 397562308

Lepidosaurs are a major vertebrate clade, with more than 9.400 species forming an ecologically diverse and geographically widespread group. Their early evolution and diversification are still poorly understood. Molecular data indicate that the two extant branches, squamates and tuataras, probably split during Triassic time. Unfortunately, lepidosaur-like fossils are very rare in Triassic rocks, which yielded only few fragmentarily known stem taxa (Lepidosauromorpha) apart from the fully established rhynchocephalians. This results from the small body size and poorly ossified skeletons as well as the poverty of fossil Lagerstaetten with good preservation potential for small tetrapods. In the Lower Keuper of Vellberg (Baden-Württemberg, SW Germany), scientific excavations have recently produced a vast number of small lepidosauromorph skeletons. The osteological analysis of these finds is time-consuming, requiring CT data in addition to extensive examination under the microscope, necessary to identify elements and fully understand the 3d structure of the often disarticulated and heavily crushed skeletons. The objectives of the proposed project are the description and documentation of the newly discovered taxa, the study of the ontogeny on the basis of preserved size classes, the phylogenetic analysis in a wide frame of diapsids, and the study of character evolution in the stem line of lepidosaurs. This project will greatly increase our understanding of how the modern ecological and taxonomic diversity of lepidosaurs first arose, and will shed more light on the evolution of diapsid reptiles on a general scale.

• DFG Programme: Research Grants