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Vjushkovisaurus
''Vjushkovisaurus'' is an extinct genus of Middle Triassic archosauriform. It is known from the Anisian-aged Donguz Gorizont in Sol-Iletsk, Orenburg Oblast, Russia. The genus was named in 1982, with the type species being ''V. berdjanensis''. Material has been collected in the Berdyanka II locality from a fossil assemblage called the ''Eryosuchus'' Fauna along the Berdyanka River, specifically in a sand-carbonate concretion in the upper part of the main river channel. ''Vjushkovisaurus'' is known only from the holotype PIN 2865/62 (formerly SGU 104/3871), a partial postcranial skeleton which consists of 12 presacral vertebrae, left humerus, ribs, a fragment of the coracoid and a fragment of the fibula.〔
==Description==
Most rauisuchids have a crest on the illium called the supra-acetabular process that overlies the head of the femur, allowing them to have a "pillar-erect" stance. As an early rauisuchid ''Vjushkovisaurus'' lacks this crest, but it does have a small thickening on the surface of the illium. The humerus differs from other better known rauisuchids in that it is shorter and broader. However, it has been suggested that the only known humerus of ''Vjushkovisaurus'' may actually belong to an aetosaur.
More recently, Nesbitt (2009) argued that ''Vjushkovisaurus'' represent most probably a valid non-archosaurian archosauriform. According to his analysis, the original diagnosis of ''Vjushkovisaurus'' by Ochev (1982) consisted of some of the plesiomorphies for Archosauriformes and characters with wide distributions throughout archosauriforms. For example, elongated anterior cervical vertebrae are present in the poposauroids, ''Yarasuchus'' (also possibly a poposauroid) and in the non-archosaurian archosauriforms ''Proterosuchus'' and ''Guchengosuchus''. Other features which are typically thought to be associated with skeletal pneumaticity, are also present in ''Guchengosuchus'', ''Erythrosuchus'', and in several archosaurs. Additionally, the shape and placement of the deltopectoral crests of the humerus of ''Vjushkovisaurus'' are typical of basal archosauriforms. The ectepicondylar groove on the humerus reported by Ochev is present in ''Prolacerta'', ''Proterosuchus'', phytosaurs, aetosaurs and several paracrocodylomorphs. Gower and Sennikov (2000) reported that the posterior cervical vertebrae bear well-defined facets for three-headed ribs. According to Nesbitt (2009), this trait is absent in Archosauria with the possible exception of ''Arizonasaurus'' and ''Poposaurus'', but was used as a synapomorphy of Erythrosuchia in Parrish (1992) phylogenetic analysis.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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