†unranked clade Megatrigonioidae van Hoepen 1929 (clam)
Bivalvia - Trigoniida - Megatrigonioidae
Parent taxon: Myophorelloidea according to J. G. Carter et al. 2011
Sister taxa: Frenguelliellidae, Myophorelloidae, Steinmanellidae
Subtaxa: Megatrigoniitae Rutitrigoniitae
Ecology: facultatively mobile infaunal suspension feeder