Crinoids; Pennsylvanian, Missourian, Virgilian; Shoemaker Limestone, Haskell Limestone, Cass Formation; Plattsmouth Limestone, Oread Formation; Jackson Park Shale, Stull Shale, Kanwaka Formation; Doniphan Shale, Beil Limestone, Avoca Limestone, Lecompton Formation; Ost Limestone, Tecumseh Formation; Ervine Creek Limestone, Deer Creek Formation; Calhoun Shale. Cass County, Nebraska, Mills, Montgomery, Fremont Counties, Iowa
Virgilian age rocks of lowa and Nebraska contain important crinoid faunas and current collections help to establish distributions and tentative ranges of numerous species. A middle limestone-core shale fauna from the Cass Formation of Nebraska provides small, usually inornate species with close Missourian affinities. Other crinoids studied are from outside shales and upper limestones of the cyclothem and these are usually large, ornate species. Biserial arms are reported for the first time for Sublobalocrinus Knapp. The first report of flexible crinoids from Virgilian strata of the Iowa-Nebraska area is made here. Current collections of crinoids contain 40 species and 31 genera representing 19 families: new species or subspecies are; Isoallagecrinus bassleri intermedius, Graffhamierinus gratesquus, Arrectocrinus iowensis, Pyndoxocrinus inornatus, Sublobacrinus kaseri, Contocrinus invaginatus, Apographiocrinus platybasis. The species Aesiocrinus luxuris is referred to the genus Moundocrinus.
Proceedings of the Iowa Academy of Science
©1980 Iowa Academy of Science, Inc.
Pabian, Roger K. and Strimple, Harrell L.
"Some Late Pennsylvanian (Virgilian) Crinoids from Southeastern Nebraska and Southwestern Iowa,"
Proceedings of the Iowa Academy of Science, 87(1), 1-19.
Available at: https://scholarworks.uni.edu/pias/vol87/iss1/3