†family Heterodiadematidae Smith and Wright 1993 (sea urchin)
Echinoidea - Calycina - Heterodiadematidae
Full reference: A. B. Smith and C. W. Wright. 1993. British Cretaceous echinoids. Part 3, Stirodonta 2 (Hemicidaroida, Arbacioida and Phymosomatoida, Part 1). Monographs of the Palaeontographical Society 147(593):199-267
Parent taxon: Phymosomatoida according to A. Kroh and A. B. Smith 2010
See also Smith 1995
Sister taxa: Boletechinus, Cottaldia, Diplopodiidae, Emiratiidae, Gauthiosoma, Leioechinus, Phymosomatidae, Polydiadematidae, Trochotiara, Zeugopleurus
Subtaxa: Loriolidiadema
Type: Heterodiadema
Ecology: slow-moving low-level epifaunal omnivore
Distribution:
• Cretaceous of Egypt (3 collections)
Total: 3 collections each including a single occurrence