Brachiopods have a hard external shell that is comprised of two asymmetrical halves called valves. The pedicle valve generally has a hole in it where the pedical or a stalk like structure like a “foot” comes out. Each half of the brachiopod shell has a slightly different shape. The Brachial valve is generally smaller than the pedicle. Brachiopods feed by filtering tiny food particles from seawater. Most of the space inside the brachiopod shell is occupied by a special organs that acts as a water pumping and filtering device.

From the Devonian deposits of Alpena, Michigan.

Top Row   Mucrospirifer and Atrypa
Middle Row   Strophodonta and Athyrus
Bottom Row  Cyrtina and Sieberella

Devonian Period
Genshaw Formation
La Farge Quarry
Alpena, Michigan.