Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 Superorder Heteroconchia Gray, 1854 Clade Heterodonta Neumayr, 1884 Order Carditida Dall, 1889 Superfamily Carditoidea Férussac, 1822 1 Family Carditidae Férussac, 1822 - little heart shells 2 Family Condylocardiidae Bernard, 1896