RE-EVALUATION OF BIOSTROME PALEOECOLOGY AT THE FALLS OF THE OHIO (MIDDLE DEVONIAN), CLARKSVILLE, INDIANA

The Falls of the Ohio State Park in Clarksville, Indiana is an important fossil locality, best known for its extensive exposure of Devonian biostrome with high levels of coral diversity. Despite the fact that coral fossils from this well-exposed location can be found in museums around the world and the location is visited often by professional and amateur paleontologists, there has been only one peer-reviewed study of the paleoecology of the biostrome by Kissling and Lineback (1967). In 2017, a new research effort began in order to reexamine the paleoecology of this important location. Fossil abundance, distribution, size, and orientation data were used to reevaluate the findings of the 1967 Kissling and Lineback study.

The study described here found that fossil orientation and distribution differed from that of Kissling and Lineback in several notable ways. The present study employed more detailed transect counting methods which involved the identification and measurement of all specimens greater than 1cm in size. In contrast, the previous study only examined fossils greater than 4 cm in size, and did not include analysis of solitary rugose corals, despite that they make up approximately 67% of the fauna in the Coral Zone. While the Kissling and Lineback study found evidence of an east/west orientation when examining elongate fossils greater than 4cm in size, a clear orientation pattern was not observed in the present study, even when fossils greater than 4cm, smaller than 4cm, or both were examined. The present study revealed a lack of bioerosion or other interactions besides coral/stromatoporoid associations. Additionally, while coral and stromatoporoids were abundant, other than a few crinoid ossicles, very few other faunal elements were observed in this horizon. These observations are consistent with what was noted by Kissling and Lineback and begs the question about why a location with such high coral diversity and dense accumulation of skeletal material contains a paucity of ecological interactions as well as low biodiversity of organisms other than coral or stromatoporoids.