Rauisuchidae

Rauisuchidae is an extinct family of large, predatory, herbivorous archosaurs that lived during the Triassic period. These reptiles were among the apex predators of their ecosystems, occupying a similar ecological niche to modern crocodilians or large carnivorous dinosaurs. They are characterized by robust builds, powerful hind limbs adapted for terrestrial locomotion, and large skulls with sharp teeth. Rauisuchids were bipedal or facultatively bipedal, meaning they could walk on two legs but also use all fours. Their exact phylogenetic position within Archosauria is debated, but they are generally considered to be a group of non-dinosaurian archosaurs, closely related to the lineage that would eventually lead to dinosaurs and crocodiles.

Fossils of rauisuchids have been found in various parts of the world, including North America, South America, Africa, and Europe, indicating a widespread distribution during the Late Triassic. Notable genera include Saurosuchus, Postosuchus, and Fasolasuchus. These animals varied in size, with some reaching lengths of up to 7 meters. Their diets likely consisted of smaller reptiles, early mammals, and possibly even smaller dinosaurs. The extinction of rauisuchids at the end of the Triassic period coincided with the rise of dinosaurs, which came to dominate terrestrial vertebrate faunas in the Jurassic and Cretaceous periods. The ecological pressures and competition from the diversifying dinosaur groups are thought to be contributing factors to their disappearance.