Pair of Ordovician Gastropod (Clathrospira) Fossils - Wisconsin

These are two examples of Clathrospira subconica, an Ordovician-aged species of gastropod. This specien is part of an old collection from the Grand Detour Formation in Beloit, Wisconsin. The gastropods have been exposed from the rock they were 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.