Maysvillian (Upper Ordovician) Chitinozoans from the Cincinnati Region of Ohio, Indiana, and Kentucky

Twenty-six chitinozoan taxa from Maysvillian (Upper Ordovician) strata from 4 sections in the Cincinnati Region are described and illustrated on 17 plates of SEM photomicrographs. Three assemblages of chitinozoan taxa are recognized. Chitinozoan relative abundance in samples is related to rock type. Changes in the chitinozoan faunas occur near lithofacies boundaries and are apparently environmentally controlled. Recurrent species associations of mutually exclusive species are widespread and can be traced over considerable distances in the Cincinnati Region. Details in the distribution patterns of chitinozoans show similarity to those exhibited by conodonts. The relations between the Maysvillian chitinozoan faunas and Late Ordovician chitinozoan faunas from other parts of the world are discussed, and their stratigraphic significance evaluated.