†family Gryphaeidae Vialov 1936 (clam)
Parent taxon: Ostreoidea according to J. G. Carter et al. 2011
Sister taxa: Arctostreidae, Chondrotidae, Eligmidae, Flemingostreidae, Ostreidae, Lithiotidae
Subtaxa: Exogyrinae, Gryphaeinae, Gryphaeostreinae, Ilymatogyra, Parahyotissa, Pycnodonteinae, Rhynchostreon
Ecology: stationary epifaunal suspension feeder