Specimens of Pseudorthoceras knoxense (McChesney) occurring in the lower part of the Cherokee Group in Marion County, Iowa, possess body chambers. The shell of these body chambers is distinctly thickened with the thickest portion of the callus on the venter. No reasonably complete peristome is preserved, but growth lines on the body chamber indicate the presence of only a broad, shallow reentrant and a broad, shallow salient.
Proceedings of the Iowa Academy of Science
©1966 Iowa Academy of Science, Inc.
Davis, Richard Arnold and Campbell, Carlyle B.
"An Orthocerid Cephalopod From the Cherokee Group of Marion County, Iowa,"
Proceedings of the Iowa Academy of Science, 73(1), 279-284.
Available at: https://scholarworks.uni.edu/pias/vol73/iss1/40