†class Blastoidea Say 1825 (blastoid)
Parent taxon: Blastozoa according to C. D. Sumrall and J. A. Waters 2012
See also Beaver et al. 1967 and Sepkoski 2002
Sister taxa: Asteroblastida, Crinoidea, Diploporita, Eocrinoidea, Glyptosphaeritida, Lepidocystoidea, Parablastoidea, Paracrinoidea, Rhombifera, Rhombifera, Soluta, Sphaeronitida
Subtaxa: Coronoidea Dissimiloblastus Eublastoidea Fissiculata Freisoblastus Granatocrinida Lotusoblastus Lysocystites Macurdablastus Spiraculata Zygocrinus
Ecology: stationary intermediate-level epifaunal suspension feeder