Occurrence, Stratigraphic Distribution, and Abundance of Chitinozoa from the Middle Devonian Columbus Limestone of Ohio

Chitinozoa from the Middle Devonian Columbus Limestone of central Ohio belong to eight species of the genera Alpneachitina, Ancyrochitina, Angochitina, Conochitina, Desmochitina, and Eisenackitina. Two new species, Ancyrochitina frankeli and Eisenackitina robusta, are described. The Chitinozoa occur in carbonate rocks such as mudstone, grainstone, and packstone that represent well-circulated open marine conditions. They are absent from dolomite which represents sediment deposited at a shallow water depositional site characterized by restricted water circulation. Comparison of the Columbus Limestone Chitinozoa with faunas from similar Middle Devonian strata in Iowa, Illinois, and Missouri indicates that the Middle Devonian Wabash Platform, located in Indiana, effectively restricted the distribution of Chitinozoa in the Illinois and Appalachian Basins.