rauisuchians

Rauisuchians are an extinct group of carnivorous archosaurs that belonged to the crocodylian line (Pseudosuchia) within Archosauria. They lived during the Middle to Late Triassic, roughly 230 to 210 million years ago, and had a wide geographic distribution, with fossils found in what is now Europe, Africa, South America, and North America.

Rauisuchians were typically large, primarily terrestrial predators. They possessed robust bodies, elongated skulls with sharp, serrated teeth, and well-developed limbs. Some members bore rows of bony osteoderms along the back. Their postcranial skeletons suggest a more erect or semi-erect gait compared with modern crocodilians, though exact limb posture varied among taxa.

In ecosystems prior to the dominance of dinosaurs, rauisuchians were among the apex terrestrial predators. They occupied river floodplains, coastal basins and arid regions, coexisting with various archosaurs, therapsids, and early dinosaurs, and likely hunted sizable prey.

Taxonomy and notable members: Rauisuchia includes genera such as Rauisuchus, Prestosuchus, Saurosuchus, Postosuchus and Fasolasuchus. They are part of Pseudosuchia, the crocodile-line archosaurs, and are more closely related to crocodilians than to birds or true dinosaurs.

Extinction and legacy: Rauisuchians declined toward the end of the Triassic, and most lineages did not survive into the Jurassic. The Triassic–Jurassic extinction event reshaped archosaur communities, paving the way for dinosaurs to become the dominant terrestrial predators.