Parent taxon: Echinodermata according to A. B. Smith and C.R.C. Paul 1982
See also Boczarowski 2001 and Parsley 1981
Sister taxa: Argonevis, Aspidocrinites, Blastozoa, Camptostromoidea, Carpoidea, Cincta, Corneotuba, Cornuvacites, Crinozoa, Ctenocystoidea, Ctenoimbricata, Echinosphaera, Edrioasteroidea, Eleutherozoa, Erinea, Fanerocoelia, Helicocystitidae, Helicoplacoidea, Homalozoa, Iheringiana, Limolepis, Nemotapis, Paracrinozoa, Pediculacaudinidae, Pelmatozoa, Radimonis, Scoteinocystis, Scutellidae, Scutellinidae, Stylophora, Tubocaudinidae, Venerella
Subtaxa: Apycnodiscidae Cyclocystoididae Moroccodiscidae
Ecology: stationary low-level epifaunal
Distribution:
• Devonian of the Czech Republic (2 collections), Poland (7), United States (2: Ohio, Tennessee)
• Silurian of Canada (1: Québec), Sweden (3), United States (16: Illinois, Indiana, Iowa, Oklahoma, Tennessee)
• Volkhov of Sweden (1)
• Ordovician of Canada (3: Ontario, Quebec), China (1), Morocco (1), the Russian Federation (1), the United Kingdom (1), United States (40: Illinois, Illinois, Iowa, Iowa, Kentucky, Minnesota, Missouri, Ohio, Oklahoma, illinois)
Total: 79 collections including 106 occurrences