Abstract
Six Early Silurian Rhodocrinitacea (Crinoidea, Camerata) are recognized from the Brassfield Formation of Ohio. Previously only a single Early Silurian rhodocrinitacean was known. The new forms include Kyreocrinus constellatus n. gen., n. sp.; Rhachicrinus wrighti n. gen., n. sp.; Silfonocrinus siluricus n. gen., n. sp.; Stereoaster squamosus Foerste; Xysmacrinus greenensis n. gen., n. sp.; and Turbocrinus punctum n. gen., n. sp. Rhachicrinus and Silfonocrinus are assigned to the Opsiocrinidae, which previously included two Devonian genera; Turbocrinus is assigned to the Anthemocrinidae; and Kyreocrinus, Stereoaster and Xysmacrinus are assigned to the Rhodocrinitidae.The Opsiocrinidae are thought to be derived from the Reteocrinidae; and a possible basis for subdividing the Rhodocrinidae is proposed, based on the arms, plating in regular interrays, presence of median ray ridges and calyx shape.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
