Balvia

Balvia is an ammonoid cephalopod genus from the Upper Devonian belonging to the goniatitid family Prionoceratidae.

Balvia Temporal range: Upper Devonian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Ammonoidea
Order:	Goniatitida
Suborder:	Tornoceratatina
Superfamily:	Prionocerataceae
Family:	Prionoceratidae
Subfamily:	Balviinae
Genus:	Balvia
Subgenera
see text

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