†Petalocardia Vincent 1925 (clam)
Bivalvia - Cardiida - Arcticidae
Parent taxon: Arcticidae according to H. E. Vokes 1980
Sister taxa: Agapella, Ambonicardia, Anisocardia, Anisocardioides, Antarctica, Antiquicyprina, Arctica, Coelocyprina, Eotrapezium, Epicyprina, Etea, Gythemon, Hartwellia, Isocyprina, Izumia, Plesiocyprina, Procyprina, Pronoella, Proveniella, Pseudotrapezium, Pygocardia, Rollierella, Roudairia, Somarctica, Staffinella, Tenea, Tortarctica, Vectianella, Venericyprina, Veniella, Venilicardia
Subtaxa: none
Ecology: facultatively mobile infaunal suspension feeder