Parent taxon: Blastozoa according to S. Zamora et al. 2017
Sister taxa: Asteroblastida, Blastoidea, Crinoidea, Diploporita, Eocrinoidea, Glyptosphaeritida, Lepidocystoidea, Parablastoidea, Paracrinoidea, Rhombifera, Soluta, Sphaeronitida
Subtaxa: none
Distribution:
• Niagaran of United States (2: Indiana, Ohio collections)
• Silurian of Canada (8: Ontario, Québec), United States (50: Arkansas, Illinois, Indiana, Iowa, Missouri, New York, Oklahoma, Tennessee, Wisconsin)
• Dobrotivian of Spain (1)
• Dawan of China (2)
• Arenig of China (3)
• Ordovician of Algeria (1), Belgium (1), the Czech Republic (3), Estonia (19), Italy (1), Norway (7), Portugal (2), Spain (4), Sweden (4), Thailand (1), the United Kingdom (7)
Total: 116 collections including 139 occurrences