Early Silurian inadunate crinoids (Brassfield Formation, Ohio)

Abstract

Eight Early Silurian inadunate crinoids are described. These include: a pisocrinid, genus and species undetermined; (?)Myelodactylus sp.; Kanabinocrinus thyaros n. gen., n. sp.; Euspirocrinus heliktos n. sp.; (?)Euspirocrinus sp.; Eoparisocrinus siluricus n. comb. (n. gen.); Dendrocrinus daytonensis n. sp.; and dendrocrinid, genus and species undetermined. Parisocrinus siluricus, Parisocrinus mulletensis, and Euspirocrinus obconicus are all reassigned to Eoparisocrinus. Parisocrinus is restricted to members of Devonian and Mississippian age. The genus Parisocrinus is discussed, and its type species P. perplexus is illustrated.Pisocrinid, genus and species undetermined, (?)Myelodactylus sp., and Kanabinocrinus thyaros represent the oldest member of the family in which each belongs. The phylogenetic relationships of these and other taxa are discussed.