"A central goal of palaeontology and evolutionary biology is to understand the drivers and dynamics of the major evolutionary radiations that have shaped the history of life on Earth and governed the origins of the modern biota. On land, one of the most important evolutionary diversifications was the radiation of archosaurs, which began around 250 million years ago following the greatest mass extinction in the history of life at the end of the Permian. This radiation gave rise to the most diverse living group of terrestrial vertebrates, the birds, as well as the most intensely studied of extinct groups, the dinosaurs. This project will focus on the early archosaur radiation during the early Mesozoic (Triassic and Jurassic), between 250 and 150 million years ago, and will constrain the diversity and biogeography of species involved in this radiation, and elucidate the radiation’s tempo and evolutionary patterns and mechanisms. Dramatic advances in recent years in data for early Mesozoic ecosystems on land, combined with rapidly advancing methodologies in virtual imaging of fossils and quantitative analysis of deep time evolutionary patterns, provide a unique window of opportunity to break through previous impasses in understanding of this event. This project will provide new insights into how and why archosaurs became arguably the most successful group of vertebrates on land, and more broadly into the nature of major evolutionary radiations, the recovery from mass extinction events, and the long-term interactions between biotic diversity and Earth system evolution. The results of this research will have important implications for understanding the origin and rise to ecological dominance of dinosaurs."