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''Nesodon'' ("island tooth")〔Palmer (1904) p. 457.〕 is a genus of Miocene mammal belonging to the extinct order Notoungulata which inhabited southern South America during the Late Oligocene to Miocene living from 29.0—16.3 Ma and existed for approximately . 〔(Paleobiology Database: ''Nesodon imbricatus'', Basic info. )〕 It had a relatively large size, weighting up to 554 kg (1221 lbs) and reaching 1.5 m in height.〔 D.Patterson, Bruce (2012) ''Bones, Clones, and Biomes: The History and Geography of Recent Neotropical Mammals'' p.92〕 ==Taxonomy== ''Nesodon'' was named by Owen (1846). It was assigned to Toxodontidae by Carroll (1988). It was an early member of the family Toxodontidae, which included the well-known Pleistocene genus ''Toxodon''. Like almost all toxodontids, ''Nesodon'' was endemic to South America. In particular, fossils of ''Nesodon'' are known from late early Miocene (Santacrucian SALMA) deposits of Argentina and Chile.〔Croft et al. (2004), p. 5.〕 Three species of ''Nesodon'' are recognized including a larger species, ''N. imbricatus'', and a smaller species, ''N. conspurcatus''.〔Croft et al. (2004), pp. 7-8.〕 A poorly known and possibly invalid third species, ''N. cornutus'', was similar to ''N. imbricatus'' but may have had a small horn on its head. All species of ''Nesodon'' were larger than species of the contemporary toxodontid ''Adinotherium''. The dentition of ''Nesodon'' shows features typical of living grazing (grass-eating) mammals, but a study of wear on the enamel of ''N. imbricatus'' suggests that it was a browser (leaf eater) that may have supplemented its diet with fruit or bark.〔Townsend & Croft (2008) p. 225.〕 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「Nesodon」の詳細全文を読む スポンサード リンク
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