Dawn of the Dinosaurs: Archosauromorph Evolution in the Terrestrial Triassic

三叠纪时期（2.52 - 2亿年前）是地球历史的关键阶段，这一时期的陆生脊椎动物群落发生了重大变化，被称为“大过渡”。原始龙形目是一个高度多样化的爬行动物（包括恐龙、翼龙、鳄鱼和鸟类），在中生代（约2亿至6500万年前）的剩余时间里多样化，随后统治了陆地生活群落。了解早期的主龙形类辐射是了解基律纳群落兴起的基础，但目前科学进展受到大多数早期主龙形类的解剖学，分类学和生殖发育学的理解不足，以及早期主龙形类的多样性和生殖发育学很少使用定量方法进行研究的事实的阻碍。我们将进行广泛的解剖学和分类学修订的几个关键组的早期archosauromorphs（原鳄科，红鳄科，Euparkeriidae，基础植龙），目的是建立他们的物种水平的多样性，单系，地理和地层分布。这些骨骼学数据将被用来开发一个新的系统发育分析的三叠纪archosauromorphs的相互关系，实质上比以前尝试的任何更全面，旨在建立一个严格的框架早期archosauromorphs进化的研究。这个新的解剖数据集将被用来定量地解决有关的时间，模式和早期初龙型多样化的速度，三叠纪的化石。我们的工作将为更全面地了解中生代陆地生态系统的曙光奠定基础。

The Triassic Period (252–200 million years ago) was a critical phase of Earth history, which saw major changes amongst terrestrial vertebrate communities that have been dubbed “The Great Transition”. The Archosauromorpha, a highly diverse group of reptiles (including dinosaurs, pterosaurs, crocodiles and birds), diversified, subsequently dominating land-living communities for the remainder of the Mesozoic (~200–65 million years ago). Understanding the early archosauromorph radiation is fundamental to understanding the rise of dinosaurian communities, but scientific progress is currently hampered by poor understanding of the anatomy, taxonomy and phylogeny of most early archosauromorph groups and the fact that the diversification and biogeography of early archosauromorphs have only rarely been examined using quantitative approaches. We will carry out extensive anatomical and taxonomic revisions of several key groups of early archosauromorphs (Proterosuchidae, Erythrosuchidae, Euparkeriidae, basal Phytosauria), with the aim of establishing their species level diversity, monophyly, and geographic and stratigraphic distributions. This osteological data will be used to develop a new phylogenetic analysis of the interrelationships of Triassic archosauromorphs, substantially more comprehensive than any previously attempted, aiming to establish a rigorous framework for studies of early archosauromorph evolution. This new anatomical dataset will be used to quantitatively address questions relating to the timing, pattern and rate of early archosauromorph diversification, and Triassic biogeography. Our work will lay a foundation for a more complete understanding of the dawn of Mesozoic terrestrial ecosystems.