Dawn of the Dinosaurs: Archosauromorph Evolution in the Terrestrial Triassic

点击翻译按钮获取中文摘要

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.