Mississippian Crinoids, Iowa Crinoids, Crinoids
Iowa Mississippian rocks, rich in fossil crinoidea, lend themselves excellently for stratigraphic zonation. Zone index fossils have been chosen in the basis of stage of evolution and abundance of occurrence. The following crinoid zones are established: North Hill formation, Aacocrinus chouteauensis (Miller), Hampton formation, Rhodocrinites kirbyi (Wachsmuth and Springer), Gilmore City formation, Rhodocrinites serpens (Laudon), Burlington formation, Dolbe Creek member, Cactocrinus proboscidialis (Hall), Haight Creek member, Agaricocrinus planoconvexus Hall, Cedar Fork member, lower part, Azygocrinus rotundus (Yandell and Shumard), upper part, Dorycrinus quinquelobus (Hall), Keokuk formation, transition beds, Eutrochocrinus trochiscus (Meek and Worthen), main limestone unit, Actinocrinites lowei (Hall), Warsaw formation, Barycrinus spurius (Hall), St. Louis formation, Dichocrinus omatus Wachsmuth and Springer and Ste. Genevieve formation, Taxocrinus huntsvillae Springer.
Proceedings of the Iowa Academy of Science
© Copyright 1973 by the Iowa Academy of Science, Inc.
Laudon, L. R.
"Stratigraphic Crinoid Zonation in Iowa Mississippian Rocks,"
Proceedings of the Iowa Academy of Science: Vol. 80:
, Article 7.
Available at: http://scholarworks.uni.edu/pias/vol80/iss1/7