2.75" Ordovician Nautiloid (Plectoceras) Fossil - Wisconsin

Ordovician Nautiloid (Plectoceras) Fossil - Wisconsin #215198

This is a 2.75" wide example of a Middle Ordovician fossil Nautiloid (Plectoceras robertsoni) from Wisconsin. This fossil is part of an old collection from the Grand Detour Formation in Rock County.

It comes with an acrylic display stand.

A nautilus's shell is made up of two layers. The inner layer has the iridescent shine, while the outer layer provides protection from external forces. Inside the shell are septa that divide the living area of the shell into compartments and help the animal maintain balance and position in the water column.

Nautilus are "living fossils": species similar to this one still exist in our oceans!