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''Andescynodon'' is a genus of traversodontid cynodont from the Middle Triassic of Argentina. Fossils are known from the Cerro de las Cabras Formation. ''Andescynodon'' is one of the most basal traversodontids. Another traversodontid called ''Rusconiodon'' has also been identified from the Cerro de las Cabras Formation but is now considered a junior synonym of ''Andescynodon''. ==Description and history== The type species ''Andescynodon mendozensis'' was named in 1967 and reported from the Rio Mendoza Formation. The location where remains have been found was later shown to be part of the Cerro de las Cabras Formation. Like all traversodontids, ''Andescynodon'' has wide postcanine teeth at the back of its jaws. These wide teeth are seen as evidence of a herbivorous diet and give traversodontids their name (their teeth are transversely wide). One distinguishing feature of ''Andescynodon'' is the forward position of a ridge on these postcanine teeth. The temporal region behind the skull is large, but smaller than those of related traversodontids. The snout is much narrower, but widens toward its tip. The skull of ''Andescynodon'' is also flatter than most traversodontids.〔 ''Rusconiodon mignonei'' was named in 1970 from the same locality as ''Andescynodon mendozensis''. ''Rusconiodon'' was distinguished from ''Andescynodon'' because it had larger canine teeth. Between the nostril openings and the canines, ''Rusconiodon'' skulls had a hole called the paracanine fossa. This fossa was also present in ''Andescynodon'' skulls, but did not emerge as a hole on the upper surface of the snout. The paracanine fossa provides room for the canine teeth of the lower jaw, which were especially large in ''Rusconiodon'' specimens.〔 The variation in size of the teeth were considered to be the result of natural intraspecific variation by Liu and Powell (2009). The skulls of ''A. mendozensis'' and ''R. mignonei'' represented one species, and because ''Andescynodon'' was named first, its name takes priority. ''Rusconiodon'' individuals have larger upper canine teeth because their overall body size is larger. Therefore, the two types represent a growth series, with ''Andescynodon'' representing smaller individuals and ''Rusconiodon'' representing larger ones.〔 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「Andescynodon」の詳細全文を読む スポンサード リンク
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