New species are still being uncovered at the Gray Fossil Site

Dr. Steven Wallace holds the beaver tooth recently discovered at the Gray fossil site. (Brian Bishop / Johnson City Press)

The Gray Fossil Site near Johnson City, Tennessee is full of surprises. The site dates to the late Miocene in age, and preserves a diverse fauna of critters. It is highly unusual to have deposits of this age preserved in the Appalachian region as most of the sediments have been stripped away from the underlying crystalline bedrock. But in this unusual setting, sediments that filled a sinkhole were preserved, along with a lot of evidence of past life from the region.

Researchers have not yet “scratched the surface” of the deposit despite several years of excavation. Core samples indicate that the deposit covers several acres and is over 100 feet thick (Wallace et al., 2002). Many species have been identified from the site including: fish; alligator; snakes; turtles; amphibians; a proboscidean; the world’s largest single collection of tapirs; rhinos; a short-faced bear; ground sloth; a saber-toothed cat; and a red panda.

They have recently added beaver to the list.

Steven Wallace and his team have identified the specimen as Dipoides, a member of an extinct line of beavers which includes the giant beaver Castoroides. Dipoides has a stratigraphic range extending from the Hemphillian to the late Blancan (Kurten and Anderson, 1980), or approximately 9 million to 3 million years ago (Prothero, 1998).

Today, you can visit a large interpretive center at the site, and watch summer excavations. It is expected that an annex will be started soon to provide even more space for visitor activities. Check it out on line at, and watch for continued news coming from Johnson City, Tennessee in paleontology.


KURTEN, B., AND E. ANDERSON. 1980. Pleistocene Mammals of North America. Columbia University Press, New York, 443 p.

PROTHERO, D. R. 1998. The chronological, climatic, and paleogeographic background to North American mammalian evolution, p. 9-36. In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.), Evolution of Tertiary Mammals of North America. Cambridge University Press, New York.

WALLACE, S. C., J. NAVE, AND K. BURDICK. 2002. Preliminary report on the recently discovered Gray Fossil Site (Miocene), Washington Co., Tennessee: with comments on observed paleopathologies and the advantages of a large sample. Journal of Vertebrate Paleontology, 22(Supplement to Number 3):117A.

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