''Chasmatosuchus'' was an

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 Gauthier ...

reptile from the early

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 ...

period of

European Russia European Russia (russian: Европейская Россия, russian: европейская часть России, label=none) is the western and most populated part of Russia. It is geographically situated in Europe, as opposed to the cou ...

. One of the earliest described archosauriforms, it was over 2 m long and is thought to have behaved like a modern

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to inclu ...

. Its mouth had two distinct features: the top of its jaw hooked downwards to aid in holding prey, and the upper palate was lined with a row of teeth—a primitive feature lost in later

archosaurs 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 ...

. ''Chasmatosuchus'' was formerly assigned to

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" ...

, but a 2016 cladistic analysis by Martin Ezcurra couldn't confidently place the species of ''Chasmatosuchus'' within Proterosuchidae. Instead their position remains unresolved due to the fragmentary nature of the known material, however ''Chasmatosuchus'' is more likely to be intermediate between proterosuchids and erythrosuchids and possibly closely related to '' Sarmatosuchus otschevi'' and '' Cuyosuchus huenei''. Ezcurra (2016) could only placed ''C. rossicus'' and ''C. magnus'' within ''Chasmatosuchus'' with certainty, while the third valid species''"C." vjushkovi'' potentially does not belong to ''Chasmatosuchus'' and may represent a proterosuchid. ''Gamosaurus'' and ''Jaikosuchus'' are subjective

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

s of ''Chasmatosuchus''.Ezcurra, M.D. (2016),The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriforms. PeerJ4:e1778;DOI10.7717/peerj.1778 ''Chasmatosuchus parvus'', based on an anterior cervical vertebra, was synonymized with ''

Macrocnemus ''Macrocnemus'' is an extinct genus of archosauromorph reptile known from the Middle Triassic (Late Anisian to Ladinian) of Europe and China. ''Macrocnemus'' is a member of the Tanystropheidae family and includes three species''. Macrocnemus bass ...

'' in 1995.Sennikov AG, 1995. Early thecodonts of Eastern Europe. Trudy Paleontologischeskogo Instituta RAN 263:1–141(in Russian).

References

Prehistoric archosauriforms Early Triassic reptiles of Europe Fossil taxa described in 1940 Prehistoric reptile genera {{triassic-reptile-stub