Full reference: J. Sprinkle and R. C. Gutschick. 1967. Costatoblastus, a channel fill blastoid from the Sappington Formation of Montana. Journal of Paleontology 41(2):385-401
Parent taxon: Spiraculata according to J. J. Sepkoski 2002
Sister taxa: Acentrotremites, Ambolostoma, Arcuoblastus, Auloblastus, Belocrinus, Calycoblastus, Carpenteroblastus, Conuloblastus, Cordyloblastus, Cribroblastus, Cryptoblastus, Decemoblastus, Deliablastus, Dentiblastus, Devonoblastus, Diploblastus, Doryblastus, Elaeacrinus, Eleutherocrinus, Ellipticoblastus, Euryoblastus, Globoblastus, Gongyloblastus, Granatocrinus, Heteroblastus, Houiblastus, Iranoblastus, Kadiskoblastus, Lophoblastus, Malchiblastus, Metablastus, Monadoblastus, Monoblastus, Monoschizablastus, Montanablastus, Nodoblastus, Nucleocrinus, Orbiblastus, Orbitremites, Pentephyllum, Pentremitidae, Pentremoblastus, Perittoblastus, Placoblastus, Poroblastus, Ptychoblastus, Pyramiblastus, Schizoblastidae, Schizoblastus, Schizotremites, Sinopetaloblastus, Strongyloblastus, Tanablastus, Tricoelocrinus, Troosticrinus, Uyguroblastus, Xinjiangoblastus, Xyeleblastus
Subtaxa: Costatoblastus sappingonensis
Ecology: stationary intermediate-level epifaunal suspension feeder