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''Valhallites'' is an extinct genus in the nautiloid order Nautilida which includes the living ''Nautilus'' found in the tropical western Pacifiic. ''Valhalites'' belongs to the Koninkioceratidae, a family in the Tainoceratacea, a nautilid superfamily. (,1964 K427) ''Valhalites'', which is given a range from the Lower Carboniferous (Mississippian) to the Lower Permian, has been found in North America (Arkansas) and Siberia. Its shell is evolute, rapidly expanding, with a depressed, elliptical whorl section. The venter is broadly rounded, the sides acute. The suture is with shallow ventral, lateral, and dorsal lobes. The shell itself bears short radial ribs, sinuous growth lines, and prominent longitudinal striae. The siphuncle is slightly ventral of the center. (ibid) The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species. ==See also== * Nautiloid * * List of nautiloids 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「Valhallites」の詳細全文を読む スポンサード リンク
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