''Archosaurus'' (meaning "ruling lizard") is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of carnivorous

proterosuchid Proterosuchidae is an early family of basal archosauriforms whose fossils are known from the Latest Permian and the Early Triassic of Europe, Asia, Africa, Australia and possibly South America. The name comes from Greek πρότερο- ("first") ...

archosauriform Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Latest Permian (roughly 252 million years ago). It was defined by Jacques Gauthie ...

reptile. Its fossils are dated to the latest Permian of

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...

and

Poland Poland, officially the Republic of Poland, , is a country in Central Europe. Poland is divided into Voivodeships of Poland, sixteen voivodeships and is the fifth most populous member state of the European Union (EU), with over 38 mill ...

, it is one of the earliest known archosauriforms. The type and only species is ''Archosaurus rossicus'', known from several fragmentary specimens which cumulatively represent parts of the skull and cervical vertebrae.Paleont. Zh. 1960 (4) It would have been long when fully grown. When first described in 1960, ''Archosaurus'' was considered the oldest known

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 ...

and a close relative of ''

Proterosuchus ''Proterosuchus'' is an extinct genus of archosauriform reptiles that lived during the Early Triassic. It contains three valid species: the type species ''P. fergusi'' and the referred species ''P. alexanderi'' and ''P. goweri''. All three spe ...

'' from 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 ...

.Tatarinov, L. P. (1960). ''Otkrytie pseudozhukhii v verkhnei permi SSSR: Paleontologischeskii Zhurnal'', 1960, n. 4, p. 74-80. However, Archosauria in modern terms is considered a more restricted group which ''Archosaurus'' lies outside of. The "classic" definition of archosaur utilized prior to the widespread use of

cladistics Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived ch ...

is now roughly equivalent to the clade Archosauriformes.Gauthier J. A. (1994): ''The diversification of the amniotes''. In: D. R. Prothero and R. M. Schoch (ed.) Major Features of Vertebrate Evolution: 129-159. Knoxville, Tennessee: The Paleontological Society. ''Archosaurus'' is still considered the oldest undisputed archosauriform, as well as one of the few valid members of the family

Proterosuchidae Proterosuchidae is an early family of basal archosauriforms whose fossils are known from the Latest Permian and the Early Triassic of Europe, Asia, Africa, Australia and possibly South America. The name comes from Greek πρότερο- ("first") ...

Gallery

File:Archosaurus rossicus.png, PIN 1100/55, the holotype left premaxilla File:Archosaurus_ross1DB.jpg, Restoration File:Archosaurus Scale.svg, Size comparison

References

Fossils of Poland Permian Russia Permian reptiles of Europe Prehistoric archosauriforms Fossil taxa described in 1960 Prehistoric reptile genera {{Permian-reptile-stub

Gallery

See also

References