†Atopechinus (sea urchin)
Echinoidea - Arbacioida - Arbaciidae
Parent taxon: Arbaciidae according to H. B. Fell and D. L. Pawson 1966
Sister taxa: Acropeltis, Acrosaster, Arbacia, Arbaciella, Arbia, Baueria, Codiopsis, Coelopleurus, Cottaldia, Glypticus, Goniopygus, Heteropodia, Magnosia, Pleiocyphus, Podocidaris
Subtaxa: none
Ecology: epifaunal grazer