Rauisuchidae

Rauisuchidae are a group of large (up to 6 meters or more) predatory Triassic archosaurs, and constitute advanced representatives of the larger group Rauisuchia. There is some disagreement over which genera should be included in the Prestosuchidae, which in Rauisuchidae, and which in the Poposauridae, and indeed whether these should even be thought of as separate families.

An early cladistic analysis of crocodylotarsan archosaurs included Lotosaurus, Fasolasuchus, Rauisuchus, and "the Kupferzell rauisuchid" (later called Batrachotomus) within Rauisuchidae. However, a later study found that Batrachotomus was more closely related to Prestosuchus, and thus was a prestosuchid. In addition, the toothless Lotosaurus has been found to be more closely related to the Ctenosauriscidae, a clade of Dimetrodon-like animals with a sail on their back.

Two genera previously classified as poposaurids, are in fact rauisuchids. These include Teratosaurus  and Postosuchus.