Family Spheniopsidae Gardner 1928 (clam)
Bivalvia - Poromyida - Spheniopsidae
Parent taxon: Cuspidarioidea according to J. G. Carter et al. 2011
See also Bieler and Mikkelsen 2006, Bouchet et al. 2010, Coan et al. 2000, Newell 1965 and Vokes 1980
Sister taxa: Cuspidariidae, Halonymphidae, Protocuspidariidae
Subtaxa: Spheniopsis
Ecology: facultatively mobile infaunal carnivore
Distribution:
• Pliocene of Belgium (1 collection)
• Miocene of United States (3: Florida)
• Oligocene of Denmark (2), United States (11: Mississippi)
• Eocene of United States (1: Mississippi)
Total: 18 collections each including a single occurrence