Cytheras

Cytheras is a genus of extinct marine mollusks belonging to the order Bivalvia. These bivalves are characterized by their flattened, equivalve shells, meaning both valves are of roughly equal size and shape. Fossil evidence indicates that Cytheras were widespread during the Mesozoic Era, particularly the Jurassic and Cretaceous periods. Their shells typically exhibit concentric growth lines, and some species may have had radial ornamentation.

The habitat of Cytheras is thought to have been shallow marine environments, where they likely lived as infaunal organisms, burrowing into soft sediment on the seafloor. Their diet would have consisted of plankton and organic detritus filtered from the water. The precise taxonomic placement of Cytheras within the bivalve class has been subject to some debate among paleontologists, but it is generally considered to be within the superfamily Ostreoidea, which also includes modern oysters.

Fossils of Cytheras have been discovered in various locations around the world, providing insights into the paleobiogeography and paleoecology of ancient seas. The study of Cytheras contributes to our understanding of bivalve evolution and the biodiversity of marine ecosystems during the Mesozoic. The genus is now extinct, and no living representatives are known.