Introduction to the fossils and geology of Cincinnati region

The rocks in and around the Cincinnati, Ohio region are packed with abundant and beautifully preserved fossils of shallow marine animals of Late Ordovician age. The strata of the Cincinnati region, in fact, comprise such an excellent record of the geology of the Late Ordovician that this interval in geologic history (approx. 451-444 million years ago) is referred to as the Cincinnatian Stage wherever rocks of this age occur in North America.

These rocks and fossils are world renowned and have been studied by numerous geologists and paleontologists starting in the late 1800’s. Consequently, the geology, sedimentology, and paleontology of these units are well understood. Many studies have discussed the paleoecology of the species that lived in these rocks and the relationships of species through time.

In the middle of the Cincinnatian Stage, an influx of species from outside the basin invaded the Cincinnati region. This event, known as the Richmondian Invasion, resulted in a complete reorganization of the ecosystem.

Previous studies of Cincinnatian paleontology have focused on analyzing species diversity and ecology, but this project and website focus on a new aspects of paleontology previously less studied in Cincinnati fossil, paleobiogeography. Paleobiogeography focuses on understanding the geographic distribution of species in space and time and trying to determine the underlying factors that determine where a species lives.

The paleobioegeographic study that this website complements was conducted using GIS (Geographic Information Systems), a computer mapping system that allows interaction with species location data, environmental data, and can plot species ranges as they change through time.

As you explore this website, you can learn about the geology of the Cincinnati region, the animals that lived here 450 million years ago, what controlled the geographic distribution of species in the past, and how ancient species invasion can help us understand the modern biodiversity crisis.