Saurischian dinosaurs from the Elliot Formation of South Africa: Anatomy, ecology, and evolution

蜥脚类恐龙起源于三叠纪，在上三叠统/下侏罗统经历了它们的初始辐射。然而，尽管上三叠世腔骨类动物的出现表明，它们的姐妹类群（包括所有后来的兽脚亚目动物）在那之后也一定存在，但它们实际上直到中侏罗世才出现在化石记录中。蜥脚类动物是上三叠统/下侏罗统许多脊椎动物群的共同代表，但由于保存不完整，无论是它们的α分类，还是它们的系统发育关系，包括蜥脚类动物的起源和早期进化问题，都没有得到解决。因此，早期蜥目动物的新材料对于更好地了解蜥目动物的初始辐射和主要类群的起源至关重要。南非和莱索托的上三叠统下艾略特组和下侏罗纪上艾略特组提供了一个独特的机会来研究蜥脚类动物及其当时的环境背景。艾略特地层以其蜥脚类动物的记录而闻名，其中包括已知最古老的蜥脚类动物Antetonitrus和Blikanasaurus，但已知的大多数分类群都是基于碎片材料，这使得对它们的分类多样性和系统发育重要性的评估变得困难。因此，在目前的项目中，为了提高我们对晚三叠世/下侏罗统蜥目动物的认识，我们计划在埃利奥特组的两个部分进行密集的实地调查。

Saurischian dinosaurs originated in the Triassic and experienced their initial radiation in the Upper Triassic / Lower Jurassic. However, although the appearance of coelophysoids in the Upper Triassic indicates that their sister group, which includes all later theropods, must have been around since then as well, they are virtually absent from the fossil record until the Middle Jurassic. Sauropodomorphs are common representatives of many vertebrate faunas of the Upper Triassic / Lower Jurassic, but, due to often incomplete preservation, neither their alpha taxonomy, nor their phylogenetic relationships are resolved, including the question of the origin and early evolution of sauropods. New material of early saurischians is therefore essential for a better understanding of the initial radiation of saurischians and the origin of major groups. The Upper Triassic Lower Elliot and Lower Jurassic Upper Elliot Formation of South Africa and Lesotho offer a unique opportunity to study saurischian faunas and their environmental context of that time. The Elliot Formation is renowned for its saurischian record, which, among others, includes the oldest known sauropods Antetonitrus and Blikanasaurus, but most taxa known are based on fragmentary material, making an evaluation of their taxonomic diversity and phylogenetic importance difficult. Thus, in the current project, intensive fieldwork in both parts of the Elliot Formation is planned in order to improve our knowledge of Late Triassic / Lower Jurassic saurischians.