[B-PT06] 地球生命史

[BPT06-P03] Can we identify Desmostylia based on only humeral morphology?

*松井 久美子¹ (1.国立科学博物館)

キーワード：分類学、古脊椎動物学、デスモスチルス類

Desmostylia is one clade of extinct marine mammals. They belong Tethyteria (Afrotheria) or Perissodactyla (Laurasiatheria) and existed during the period between the early Oligocene and late Miocene. All occurrences of their fossils are limited to marine strata along the coasts of the North Pacific Ocean. Desmostylian fossils in many shapes and forms, including whole or partial skeletons, skulls, teeth, and fragmentary bones have been discovered from both Pacific coasts, but detailed taxonomic identification based on fragmentary or isolated postcranial materials has been difficult owing to our limited knowledge of the postcranial diagnostic features of desmostylian taxa.

For this reason, I established desmostylian diagnostic characters found in the humerus to identify desmostylian genus. I could found 6 diagnostic characters for desmostylia, 5 diagnostic characters for Behemotops, 7 diagnostic characters for Archaeoparadoxia, 7 diagnostic characters for Paleoparadoxia, 4 diagnostic characters for Neoparadoxia, 6 diagnostic characters for Ashoroa, and 6 diagnostic characters for Desmostylus. All these characters found in this study can be used to identify isolated desmostylian humeri to genus level. Therefore, these results will contribute a better understanding of the stratigraphic and geographic distribution of each desmostylian genus.