Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 Superorder †Nepiomorphia Kříž, 2007 Order †Praecardiida Newell, 1965 Superfamily †Cardioloidea Hoernes, 1884 1 Family †Cardiolidae Hoernes, 1884 2 Family †Slavidae Kříž, 1982