The Warsaw Formation is a geologic formation in Illinois, Iowa and Missouri. It preserves fossils dating back to the Mississippian subperiod. Brachiopod, bryozoan, and crinoid fossils are common, particularly the bryozoan Archimedes.
See also
List of fossiliferous stratigraphic units in Illinois List of fossiliferous stratigraphic units in Iowa List of fossiliferous stratigraphic units in Missouri
References