†order Cyrtodontida Scarlato and Starobogatov 1971 (clam)
Parent taxon: Arcioni according to J. G. Carter et al. 2011
See also Bouchet et al. 2010 and Nevesskaja 2009
Sister taxon: Arcida
Subtaxa: Aegilops Cyrtodontidina Praecardiidina
Ecology: facultatively mobile epifaunal suspension feeder