Liostrea is a genus of extinct oysters, marine bivalve mollusks in the family Gryphaeidae.

[1] These fossils range from the early Triassic Period[2] to the Cenomanian Epoch of the late Cretaceous Period and were widely distributed geographically.

The species L. erina[3] and L. roemeri[4] attached themselves to living ammonoids.

Liostrea formed abundant ostreoliths (concretions composed of encrusting organisms) on the hardgrounds of the Jurassic Carmel Formation in southwestern Utah.

This suggests oysters emerged and rapidly diversified in the wake of the Permian-Triassic extinction event.