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

鳞翅龙是一个主要的脊椎动物分支，有9400多个物种，形成了一个生态多样、地理分布广泛的群体。它们的早期进化和多样化仍然知之甚少。分子数据表明，现存的两个分支，鳞片和鳄蜥，可能在三叠纪时期分裂。不幸的是，在三叠纪岩石中，鳞翅目类化石非常罕见，除了完全确定的舌头类外，只有少数已知的茎类（鳞翅目）。这是由于体型小，骨骼骨化不良，以及缺乏具有良好保存潜力的小型四足动物化石Lagerstaetten。在Vellberg的Lower Keuper（德国西南部的baden - w<e:1> - rttemberg），科学发掘最近发现了大量鳞片人猿的小骨架。这些发现的骨学分析是耗时的，除了在显微镜下进行广泛的检查外，还需要CT数据，这是识别元素和充分了解经常脱节和严重破碎的骨骼的三维结构所必需的。本项目的目标是对新发现的类群进行描述和文献记录，在保存的大小类的基础上进行个体发生研究，在大范围内对鳞龙进行系统发育分析，并研究鳞龙茎系的性状进化。该项目将大大增加我们对鳞翅龙现代生态和分类学多样性如何产生的理解，并将在一般规模上对蹼足类爬行动物的进化有更多的了解。

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.