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''Typothorax'' is an extinct genus of typothoracisine aetosaur that lived in the Late Triassic. Its remains have been found in North America. Two species are known: ''T. coccinarum'', the type species, and ''T. antiquum''. ==Description== ''Typothorax'' was an aetosaur, a pseudosuchian distantly related to modern crocodilians. Unlike modern crocodilians, aetosaurs were herbivorous. ''Typothorax'' and other aetosaurs possess small, leaf-shaped teeth that were unsuited for a diet consisting of meat.〔Martz, J.W. 2002. The morphology and ontogeny of Typothorax coccinarum (Archosauria, Stagonolepididae) from the Upper Triassic of the American southwest. M.S. thesis, Geosciences, Texas Tech University, Lubbock, 279 pp.〕 Unlike some aetosaurs such as ''Desmatosuchus'', ''Typothorax'' does not have large shoulder spikes.〔〔 It does, however, have a pair of enlarged spikes on the neck projecting from the third row of scutes. It has lateral scutes that bear horns that are posteriorly hooked along its back, while its sides and underbelly are covered with ornamented scutes. Although fossils of aetosaurs are not as common as other Triassic archosaurs, with their armor plates being the most common, ''Typothorax'' has been represented by fewer skeletal elements than other aetosaurs. ''Typothorax'' was about long and weighed . The vertebral column of ''Typothorax'' is shortened, with individual vertebrae being reduced in length. However, the osteoderms that overly the vertebrae are not shortened. Instead, they are reduced in number so that each dorsal paramedian osteoderm (osteoderm that covers the back) overlies several dorsal vertebrae. In nearly all other crurotarsans, there is one row of osteoderms per vertebra. ''T. coccinarum'' has around 20 rows of presacral osteoderms and about 26 presacral vertebrae. If the cervical spikes of ''Typothorax'' are homologous to those of ''Desmatosuchus'', it is likely that rows of osteoderms were removed from the front. This is because in ''Desmatosuchus'' the spikes are present in the fifth row, while in ''Typothorax'' they are present in the third. In ''T. coccinarum'', there are 10 thoracic columns and four caudal columns of ventral osteoderms on the underside. Unlike all other aetosaurs, ''Typothorax'' possesses spiked osteoderms on the underside of the tail, near the cloaca. This region is not covered by osteoderms to the extent that it is in other aetosaurs such as ''Aetosaurus'' and ''Coahomasuchus''. 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「Typothorax」の詳細全文を読む スポンサード リンク
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