Crassostrea is a genus of true oysters containing some of the most important oysters used for food.
Crassostrea
Crassostrea gigantissima (Finch, 1824) from the Eocene of Texas.
Crassostrea gigantissima (Finch, 1824) right valve interior (Eocene of Texas).
The Ostreidae, the true oysters, include most species of molluscs commonly consumed as oysters. Pearl oysters are not true oysters, and belong to the order Pteriida.
Ostreidae
Crassostrea rhizophorae