Permalink : http://hdl.handle.net/2115/36754

Three species of Crotalocrinitidae crinoids, Pernerocrinus hayasaki (Minato and Minoura), P. per-foratus sp. nov. and P. sp. are described. All these species came from the lower part of the Ohno Formation (Lower Devonian) of the southern Kitakami Mountains. The first species was previously describcd as a tabulate coral, Ohnopora hayasakai gen. et sp. nov., belonging to the family Syringolitidae. Robust construction of the Pernerocrinus is interpreted to be especially well adapted to reef environment and its occurrence is strictly confined, at present, to the Lower Devonian.