Liostrea

Liostrea is a genus of extinct oysters, marine bivalve mollusks in the family Gryphaeidae.^[1]

Liostrea Temporal range: 252–94 Ma PreꞒ Ꞓ O S D C P T J K Pg N early Triassic - Cenomanian
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Ostreida
Family:	Gryphaeidae
Subfamily:	†Gryphaeinae
Genus:	†Liostrea Douvillé, 1904

These fossils range from the early Triassic Period^[2] to the Cenomanian Epoch of the late Cretaceous Period and were widely distributed geographically. They were encrusting organisms, attaching firmly to the substrate on their left shell, and were important Jurassic reef-forming organisms. 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.^[5]

Liostrea may be the earliest oyster lineage, with possible examples attached to ammonoids of the earliest Triassic. This suggests oysters emerged and rapidly diversified in the wake of the Permian-Triassic extinction event.^[2]

Selected species

• L. erina d'Orbigny^[3]
• L. oxiana Romer^[3]
• L. plastica Trautschold)^[3]
• L. roemeri Quenstedt, 1843^[4]
• L. saratoviensis Ivanov 2001^[6]
• L. volgensis Ivanov 2001^[6]