Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 Superorder Heteroconchia Gray, 1854 Clade Heterodonta Neumayr, 1884 Order Pholadomyida Newell, 1965 Superfamily Pholadomyoidea King, 1844 Family †Sanguinolitidae Miller, 1877 Subfamily †Undulomyinae Astafieva-Urbajtis, 1983