Full reference: J. W. Durham and K. E. Caster. 1963. Helicoplacoidea: a new class of echinoderms. Science 140(3568):820-822
Parent taxon: Echinodermata according to J. W. Durham and K. E. Caster 1963
See also Sepkoski 2002
Sister taxa: Argonevis, Aspidocrinites, Blastozoa, Camptostromoidea, Carpoidea, Cincta, Corneotuba, Cornuvacites, Crinozoa, Ctenocystoidea, Ctenoimbricata, Cyclocystoidea, Edrioasteroidea, Eleutherozoa, Erinea, Fanerocoelia, Helicocystitidae, Holothuroidea, Homalozoa, Iheringiana, Limolepis, Nemotapis, Paracrinozoa, Pediculacaudinidae, Pelmatozoa, Radimonis, Scoteinocystis, Scutellidae, Scutellinidae, Stylophora, Tubocaudinidae, Venerella
Subtaxa: Helicoplacida Helicoplacidae Polyplacida Westgardellidae
Ecology: stationary low-level epifaunal suspension feeder