from 13 localities in Missouri and Illinois
Midwestern USA USA
Geological Time: Carboniferous Mississippian Lower Mississippian
Hannibal Formation
images are shown with permission of the journal micropaleontology and
are provided by
classified by Conkin and Conkin as Proteonina, which is nowadays unaccepted
The identification is based upon:
Conkin, James E., Conkin, Barbara M. and Pike, James W., 1965: