Bivalvia, cf. Deltopecten

A large, coarsely ribbed bivalve of scallop form, with the two valves mirroring each other left and right — the opposite arrangement to a brachiopod.

Deltopecten is a characteristic bivalve of the cold-water Permian seas of eastern Australia and reached a considerable size. The fan-with-ears outline is the same shape used, from a living relative, as the Shell petroleum emblem.