Solemyoidea

Solemyoidea, formerly Cryptodonta, are a nearly-extinct superfamily of the bivalves.

Solemyoidea
Solemya elarraichensis holotype
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Solemyida
Superfamily:	Solemyoidea Gray, 1840
Families[1]
†Clinopisthidae Pojeta, 1988 †Ctenodontidae Wöhrmann, 1893 †Ovatoconchidae J. G. Carter, 2011 Solemyidae Gray, 1840
Synonyms[1]
Cryptodonta[2]

The valves of the shell are relatively thin and somewhat elongated. Unlike most other bivalves, species in this group have no hinge teeth on their shells. They have relatively primitive, "protobranchiate", gills.^[3]