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