| Dry Dredgers: An association of amateur geologists dedicated to the knowledge and enjoyment of fossils. Based in Cincinnati, Ohio. |
| Bill Heimbrock's Ordovician Paradise: A gallery of fossils from the Upper Ordovician strata of the Cincinnatian Series. |
| Cincinnatian Fossils of the Ordovician Period: Contains photographs and descriptions of fossils collected from the Cincinnatian Series. |
| Cincinnatian Trilobites: Information about trilobites from the Upper Ordovician Period Cincinnatian Seiries of Eastern North America. Includes images and links. |
| Limper Geology Museum at Miami University: Fossil collection of primarily southwestern Ohio, northern Kentucky, and eastern Indiana Upper Ordovician. |
| The Paul Sanders Fund: Fund supported by the Cincinnati Dry Dredgers offering small grants to researchers working on fossils of the Cincinnatian Series and other fossils in the area. |
| The Type Cincinnatian: Compilation of information about the Cincinnatian from Richard Davis. Includes extensive bibliography and alphabetical listing of all known genera. |
Classical
