FOSSIL SCALLOP SHELLS
Scallops are common marine bivalves in much of the fossil record and in the modern oceans. Individual bivalve shells, unlike brachiopod shells, are asymmetrical. Scallop shells sometimes approach bilateral symmetry, but the subtriangular, wing-like auricles along the hingeline will still display asymmetry. One of the auricles has a basal notch. A notched auricle on the right side of a shell indicates a right valve. A notched auricle on the left side of a shell indicates a left valve.
Carolinapecten eboreus (Conrad, 1833) (above & below) (4.9 cm across at its widest) - this fossil scallop shell is from the Yorktown Formation (Lower to Middle Pliocene) at the Lee Creek Phosphate Mine (southern shore of Pamlico Sound, near Aurora, southern Beaufort County, eastern North Carolina).
This is a right valve (anterior is to the right).
Classification: Mollusca, Bivalvia, Pteriomorphia, Pterioida, Pteriina, Pectinoidea, Pectinidae
Placopecten clintonius (Say, 1824) (5.0 cm across at its widest) - here’s another scallop shell from the Yorktown Formation (Lower to Middle Pliocene) at the Lee Creek Phosphate Mine (southern shore of Pamlico Sound, near Aurora, southern Beaufort County, eastern North Carolina). This is a left valve (anterior is to the left).
Classification: Mollusca, Bivalvia, Pteriomorphia, Pterioida, Pteriina, Pectinoidea, Pectinidae)