Class Bivalvia Linnaeus, 1758 - bivalves Status: extant Subclass Autobranchia Grobben, 1894 Status: extant Superorder Heteroconchia Gray, 1854 Status: extant Clade Heterodonta Neumayr, 1884 Status: extant Order †Hippuritida Newell, 1965 Status: fossil 1 Superfamily †Radiolitoidea d'Orbigny, 1847 Status: fossil 2 Superfamily †Requienioidea Kutassy, 1934 Status: fossil