†Undularia (Stereokion) (snail)
Gastropoda - Ptenoglossa - Protoculidae
Alternative spelling: Stereokion
Parent taxon: Undularia according to Tichy 1980
See also Sepkoski 2002
Sister taxa: Undularia (Orthostomia), Undularia disputata, Undularia scalata
Subtaxa: none
Ecology: epifaunal carnivore
Distribution: found only at Lewiston locality (Triassic of Idaho)