1.1" Ordovician Bivalve (Tancrediopsis) Fossil - Wisconsin

Ordovician Bivalve (Tancrediopsis) Fossil - Wisconsin #248572

This is a 1.1" wide (each half) fossil of the Middle Ordovician bivalve mollusk Tancrediopsis gibberula. The specimen contains two separate fossils, one stacked over the other. This fossil is part of an old collection from the Grand Detour Formation in Beloit, Wisconsin. It has been exposed from the rock it was found in.

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.