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''Coelophysis kayentakatae'' is an extinct species of coelophysid dinosaur that lived approximately 196 million years ago during the early part of the Jurassic Period in what is now the southwestern United States. Originally included in the genus ''Syntarsus'', a name which was later found to have already been in use for a species of insect. It has been reclassified as either ''Coelophysis'' or ''Megapnosaurus'', along with the African species, ''Coelophysis rhodesiensis''. The name ''C. kayentakatae'' refers to the Kayenta Formation, where all known fossil specimens have been found. ==Description== ''C. kayentakatae'' had small two small, parallel crests and may show an evolutionary step toward later and larger neotheropods, such as the more advanced and larger ''Dilophosaurus''. Both possess a "weak joint" between the premaxillary and the maxillary bones, creating a hooked premaxillary jaw. Specimen UCMP V128659 was discovered in 1982 and referred to ''Syntarsus kayentakatae'' by Rowe in 1989,〔Rowe, (1989). A new species of the theropod dinosaur Syntarsus from the Early Jurassic Kayenta Formation of Arizona. Journal of Vertebrate Paleontology. 9, 125-136.〕 as a subadult gracile individual and later, Tykoski (2005)〔Tykoski, 1998. The osteology of Syntarsus kayentakatae and its implications for ceratosaurid phylogeny. Unpublished Masters Thesis, University of Texas at Austin, 217 pp.〕 agreed. Gay (2010) described the specimen as the new tetanurine taxon ''Kayentavenator elysiae'',〔Gay, 2010. Notes on Early Mesozoic theropods. Lulu Press. 44 pp.〕 but Mortimer (2010) pointed out that there was no published evidence that ''Kayentavenator'' is the same taxon as ''C. kayentakatae''. A diagnosis is a statement of the anatomical features of an organism (or group) that collectively distinguish it from all other organisms. Some, but not all, of the features in a diagnosis are also autapomorphies. An autapomorphy is a distinctive anatomical feature that is unique to a given organism or group. According to Tykoski and Rowe (2004) ''Megapnosaurus kayentakatae'' can be distinguished based on the following characteristics: * the presence of nasal crests on the skull * the frontal bones on the skull are separated by a midline anterior extension of the parietal bones 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Coelophysis kayentakatae」の詳細全文を読む スポンサード リンク
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