Rauisuchidae is a group of large predatory Triassic archosaurs. Some disagreement exists over which genera should be included in the Rauisuchidae and which should be in the related Prestosuchidae and Poposauridae, and indeed whether these should even be thought of as separate valid families. Rauisuchids occurred throughout much of the Triassic, and may have first occurred in the Early Triassic if some archosaurian taxa such as Scythosuchus and Tsylmosuchus are considered to be within the family.
Rauisuchidae
Archosauria is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term, which includes birds. Extinct archosaurs include non-avian dinosaurs, pterosaurs and extinct relatives of crocodilians. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives; and Avemetatarsalia, which includes birds and their extinct relatives.
Archosaur
Examples of pseudosuchians. Clockwise from top-left: Longosuchus meadei (an aetosaur), Gavialis gangeticus (a crocodilian), Saurosuchus galilei (a loricatan), Pedeticosaurus leviseuri (a sphenosuchian), Chenanisuchus lateroculi (a dyrosaurid), and Dakosaurus maximus (a thalattosuchian).
Examples of avemetatarsalians. Clockwise from top-left: Tupuxuara leonardi (a pterosaur), Alamosaurus sanjuanensis, (a sauropod), Tsintaosaurus spinorhinus (an ornithopod), Daspletosaurus torosus (a tyrannosaurid), Pentaceratops sternbergii (a ceratopsian), and Grus grus (a neornithian).
Chirotherium footprint in Triassic sediments