Clade Microstomata Smith 1984 (sea urchin)
Full reference: A. B. Smith. 1984. Echinoid Palaeobiology. Allen & Unwin, London 1-190
Parent taxon: Irregularia according to A. Kroh and A. B. Smith 2010
See also Kiessling 2003 and Smith 1984
Sister taxa: Atelostomata, Echinoneoida, Holectypoida, Pygasteridae
Subtaxa: Desorellidae Galeropygidae Hyboclypus Neognathostomata Pygorhytis
Ecology: epifaunal grazer-deposit feeder