Rauisuchidae is a group of large (up to or more) predatory

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

archosaur Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avi ...

s. There is some disagreement over which genera should be included in Rauisuchidae and which should be in the related Prestosuchidae and Poposauridae, and indeed whether these should even be thought of as separate valid

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

. Rauisuchids occurred throughout much of the Triassic, and may have first occurred in the

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a ...

if some archosaurian taxa such as '' Scythosuchus'' and '' Tsylmosuchus'' are considered to be within the family. An early cladistic analysis of crocodylotarsan (

pseudosuchia Pseudosuchia is one of two major divisions of Archosauria, including living crocodilians and all archosaurs more closely related to crocodilians than to birds. Pseudosuchians are also informally known as "crocodilian-line archosaurs". Prior to ...

s included '' Lotosaurus'', '' Fasolasuchus'', ''

Rauisuchus ''Rauisuchus'' (meaning "Wilhelm Rau's crocodile") is a genus of extinct archosaurs which lived in what is now the Geopark of Paleorrota ( Santa María Formation), Brazil, during the Late Triassic period (235–228 million years ago). It con ...

'', and "the Kupferzell rauisuchid" (later called '' Batrachotomus'') within Rauisuchidae.Parrish JM. 1993. Phylogeny of the Crocodylotarsi, with reference to archosaurian and crurotarsan monophyly. ''Journal of Vertebrate Paleontology'' 13: 287-308. However, a later study found that '' Batrachotomus'' was a more

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

pseudosuchian only slightly more "advanced" than '' Prestosuchus''.Gower DJ. 2002. Braincase evolution in suchian archosaurs: evidence from the rauisuchian ''Batrachotomus''. ''Zoological Journal of the Linnean Society'' 136: 49-76. In addition, the toothless ''Lotosaurus'' has been found to be more closely related to the Ctenosauriscidae, a clade of

poposauroids Poposauroidea is a clade of advanced pseudosuchians (archosaurs closer to crocodilians than to dinosaurs). It includes poposaurids, shuvosaurids, ctenosauriscids, and other unusual pseudosuchians such as ''Qianosuchus'' and '' Lotosaurus''. H ...

with sails on their backs.Nesbitt SJ. 2005. Osteology of the Middle Triassic pseudosuchian archosaur ''Arizonasaurus babbitti''. ''Historical Biology'' 17: 19-47. Two genera previously classified as poposaurids, are in fact rauisuchids. These include ''

Teratosaurus ''Teratosaurus'' is a genus of rauisuchians known from the Triassic Stubensandstein (Löwenstein Formation - Norian stage) of Germany. It is estimated to be 6 meters (19.5 ft) long. Discovery In 1860, Sixt Friedrich Jakob von Kapff at ...

''Long RA, Murry PA. 1995. Late Triassic (Carnian and Norian) tetrapods from the Southwestern United States. ''New Mexico Museum of Natural History & Science Bulletin'' 4: 1-254.Galton PM, Walker AD. 1996. ''Bromsgroveia'' from the Middle Triassic of England, the earliest record of a poposaurid thecodontian reptile (Archosauria: Rauisuchia). ''Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen'' 201 (3): 303-325. and ''

Postosuchus ''Postosuchus'', meaning "Crocodile from Post", is an extinct genus of rauisuchid reptiles comprising two species, ''P. kirkpatricki'' and ''P. alisonae'', that lived in what is now North America during the Late Triassic. ''Postosuchus'' is a ...

''.Weinbaum JC, Hungerbühler A. 2007. A revision of ''Poposaurus gracilis'' (Archosauria: Suchia) based on two new specimens from the Late Triassic of the southwestern U.S.A. ''Paläontologische Zeitschrift'' 81(2):131-145.

Genera

References

External links

Taxon Search - Rauisuchidae

- Mikko's Phylogeny Archive.

- Dinosaur Mailing List archives

- Dinosaur Mailing List archives {{Taxonbar, from=Q134295 Early Triassic first appearances Late Triassic extinctions Prehistoric reptile families