1.2" Ordovician Gastropod & Oncoceratid Fossils - Wisconsin

Ordovician Gastropod & Oncoceratid Fossils - Wisconsin #224848

This is a 1.2" wide example of Trochonema beloitense, a species of Ordovician-aged gastropod, associated with a partial oncoceratid of the genus Beloitoceras. 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.