Pennsylvanian, Virgi lian; Wolfcampian; Beil Limestone; Lecompton Formation; Curzon Limestone; Topeka Formation; Arrectocrinus range zone; Cass County, Nebraska; Montgomery County, Iowa; Arrectocrinus hopperi. A. stanleyi, A. comminutus
New species of Arrectocrinus Knapp from southwestern Iowa and southeastern Nebraska. Partial crowns of Arrectocrinus hopperi n.sp. show that the formerly poorly known arms of this genus are biserial and probably did not expand distalward. The Arrectocrinus range zones lowered to include the Beil Limestone Member of the Lecompton Formation (Virgilian). Possible affinities of Arrectocrinus with Erisocrinus are examined.
Proceedings of the Iowa Academy of Science
© Copyright 1977 by the Iowa Academy of Science, Inc.
Pabian, Roger K. and Strimple, Harrell L.
"New Species of Arrectocrinus Knapp from Southwestern Iowa and Southeastern Nebraska,"
Proceedings of the Iowa Academy of Science, 84(3), 106-109.
Available at: https://scholarworks.uni.edu/pias/vol84/iss3/5