Class Bivalvia Linnaeus, 1758 - bivalves Subclass Protobranchia Pelseneer, 1889 Order Nuculanida Carter, Campbell & Campbell, 2000 [monotypic] Superfamily Nuculanoidea Adams & Adams, 1858 (1854) Family †Polidevciidae Kumpera, Prantl & Růžička, 1960, incertae sedis