Crinoids from the Muldraugh Member of the Borden Formation in north-central Kentucky (Echinodermata, Lower Mississippian)

Abstract

A new late Osagean (Lower Mississippian) crinoid fauna is described from the Muldraugh Member of the Borden Formation of central Kentucky. The Muldraugh Member records a mixed carbonate-siliciclastic tempestite-dominated ramp environment. This is the first report of late Osagean crinoids from this depositional setting on the eastern side of the Eastern Interior Basin of the midcontinental United States. The Muldraugh crinoid fauna contains 66 species and is dominated by advanced cladids. This fauna has similarities to other late Osagean faunas but is distinctive both in species abundance and rank order abundance of species. Eight new species are described from this fauna, includingCamptocrinus nudus, Paradichocrinus ramus, Poteriocrinites horowitzi, Parascytalocrinus pentagonus, Abrotocrinus debrae, Abrotocrinus springeri, Worthenocrinus hardinensis, andMespilocrinus myllos.