†order Pygasteroida Durham and Melville 1957 (sea urchin)
Full reference: J. W. Durham and R. V. Melville. 1957. A classification of Echinoids. Journal of Paleontology 31:242-272
Parent taxon: Diadematacea according to H. B. Fell 1966
See also Durham and Melville 1957 and Sepkoski 2002
Sister taxa: none
Subtaxa: none
Ecology: slow-moving low-level epifaunal grazer
Distribution: there are no occurrences of Pygasteroida in the database