Conodonts from the Keokuk, Warsaw, and Salem Formations (Mississippian) of Illinois

The Warsaw and Salem Formations in the Mississippi Valley area have produced a conodont fauna consisting of eleven genera and seventeen species, four of which are new. The fauna is relatively sparse and is numerically dominated by only two species, Gnathodus texanus and Taphro gnathus varians . Several sections of the Keokuk Formation yielded a fauna that is dominated by Gnathodus texanus . Otherwise the fauna is much like that of the Warsaw-Salem. Differences in abundance of conodont species seem to indicate that the units can be biostratigraphically subdivided.