Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 Superorder Heteroconchia Gray, 1854 Clade Heterodonta Neumayr, 1884 Order Pholadomyida Newell, 1965 Superfamily Pandoroidea Rafinesque, 1815 Family Lyonsiidae Fischer, 1887