2.8" Ordovician Gastropod and Bivalve - Wisconsin

Ordovician Gastropod and Bivalve - Wisconsin #248617

This is a 2.8" wide association of the Middle Ordovician gastropod Liospira vitruvia and a bivalve of the genus Cyrtodontula. This fossil is part of an old collection from the Grand Detour Formation in Beloit, Wisconsin.

Gastropods, or snails, have been around since the Late Cambrian period. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. There are 611 known families of gastropods, of which 202 families are extinct and appear only in the fossil record.