The stem-archosaur evolutionary radiation in South America

The oldest archosauromorphs (dinosaurs, birds, crocodiles, and their stem-taxa) are recorded in middle?upper Permian rocks, but it was not after the Permo?Triassic mass extinction that group shows a substantially high taxonomic richness ecomorphological disparity. early evolutionary history of Archosauromorpha during Early Middle Triassic is mainly based on fossils recovered from rocks southern Africa, Europe Asia, whereas South America possesses more complete fossil record only Late Triassic. Here we revisit, discuss, reanalyse non-archosaurian archosauromorph current-day America. this continent still scarce, documents evolution western Pangaea crucial to understand globally biotic recovery extinction. extremely assemblage among most diverse abundant worldwide. last decade has witnessed considerable improvement our knowledge record, taxonomy, phylogeny, macroevolution with input American fossils. Nevertheless, amount research needed ideally should be focused some particular aspects radiation Archosauromorpha. Among them, expanded, numerous specimens have picture group, taxonomy groups like proterochampsids hyperodapedontine rhynchosaurs clarified through detailed anatomical work.