Crinoids and stelleroids (Echinodermata) from the Broken Rib Member, Dyer Formation (Late Devonian, Famennian) of the White River Plateau, Colorado

A crinoid and stelleroid fauna is described from the Famennian (Late Devoni an) Broken Rib Member of the Dyer Formation of the White River Plateau, Col orado. The fauna postdates the Late Devonian extinction event. Six new crin oid species described, including the new genus Tarassocrinus, are: Strimple crinus dyerensis, Catactocrinus? torus, Hypselacrinus? bisonensis, Gilmocri nus? albus, Eireocrinus? coloradoensis, and Tarassocrinus synchlydus. The c ladid-dominated crinoid fauna is transitional between earlier Devonian and later Carboniferous faunas. It contains the first report of Cupressocrinite s (a Famennian Lazarus taxon) and Eireocrinus? in North America and extends ranges of several Carboniferous genera into the Late Devonian. A prelimina ry revision of the Rhenocrinidae is recommended. The family Glossocrinidae is recognized, and the Cupressocrinitidae are transferred to the Gasterocom acea. A new stelleroid genus and species, Pleiadenster inceptus (Asteroidea; fami ly unknown), and an ophiuroid, Ophiopolytretus aethus (Ophiuroidea; Lapwort huridae?) are named. In addition, Hudsonaster (Hudsonasteridae; Asteroidea) and two unassigned asteroids are present, and three further stelleroids ca nnot be assigned to the class level. Pleiadeaster and Hudsonaster are impor tant because they suggest that the Late Devonian might have been a time of transition for asteroids. Ophiopolytretus aethus is an oegophiurid ophiuroi d with distinctive respiratory? pores penetrating the disk plates.