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''Balvia'' is an ammonoid cephalopod genus from the Upper Devonian belonging to the goniatitid family Prionoceratidae. ''Balvia'' has a small, lenticular to subglobular shell with a punctate umbilicus, that is completely involute. Growth lines are fine, forward slanting, concavo-convex; indicate well developed ventrolateral salients and hyponomic sinus. Flanks have several weak constrictions, which usually swing forward at venter to form grooves bounding a median keel. The aperture may be modified. ''Balvia'' was named by Dieter Korn in 1994 with the redescription of the type species, ''Gattendorfia globularis'' originally described by Schmidt in 1924. The genus was further divided into the subgenera ''B.(Balvia)'', ''B. (Mayneoceras)'', and ''B.(Kenseyoceras)'' by Becker in 1996. ==References== *(Saunders et al 1999 Evolution of Complexity in Paleozoic Ammonoid Sutures; Supplementary Material. Science Mag. ) *(''Balvia'' in Goniat ) *(The Paleobiology Database accessed 10/01/07 ) 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「Balvia」の詳細全文を読む スポンサード リンク
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