Late Mississippian; Chesterian; Talarocrinus Zone; Pella Formation; Mahaska County, Iowa; Echinodermata; Echinoidea; Echinocystitidae; Praepholidocidaris pellaensis; Pholidocidaris; paleoecology
Praepholidocidaris pellaensis, n. gen., n. sp., is described from basal Chesterian rocks in the vicinity of Oskaloosa and Givin, Mahaska County, Iowa. The new genus is characterized by its small number of ambulacral and interambulacral plate columns, adorally expanded ambulacra, unequal ambulacrals with perforate primary spines, and interambulacrals with primary spines only on adradial plate columns. Age relationships of the Pella Formation and the paleoecology of its echinoderm fauna are reviewed. It is concluded that the echinoderms represent an opportunistic assemblage and the bulk of the echinoderm fauna supports assignment of unit C of the formation to the Talarocrinus Zone (of Horowitz and Strimple, 1974), basal Chesterian.
Proceedings of the Iowa Academy of Science
©1977 Iowa Academy of Science, Inc.
Frest, T. J. and Strimple, H. L.
"Praepholidocidaris, a New Echinoid from the Pella Formation (Mississippian) of Iowa,"
Proceedings of the Iowa Academy of Science, 84(3), 98-105.
Available at: https://scholarworks.uni.edu/pias/vol84/iss3/4