Phylum: Mollusca (Mollusks)

Class: Rostrochonchia 
(primitive molluscs)

The Rostroconchia is a class of extinct mollusks dating from the early Cambrian to the late Permian. They were initially thought to be bivalves, but were later given their own class.  More Info.

Apotocardium sp. Formation: Graham  Period:  Pennsylvanian  (c. 300 mya) Location: Jack co., Tx. Feb. 20, 2010.

Apotocardium sp. Formation: Graham  Period:  Pennsylvanian  (c. 300 mya) Location: Jack co., Tx. Feb. 20, 2010.