The Gray Fossil Site is an Early Pliocene collection of fossils between 4.5 and 4.9 million years old. It is near the town of Gray in Washington County, Tennessee.
The site was discovered during road construction in May 2000. Local officials decided to preserve the site for research and education. The site is part of East Tennessee State University, and the Gray Fossil Site & Museum opened on the site in 2007.
Once, the land around the Gray Fossil Site was a pond inside a sinkhole surrounded by a warm, wet forest. The fossils found in the area show what lived and died in and around the sinkhole pond.
As the first site of its age known from the Appalachian region, the Gray Fossil Site is a unique window into the past. Research at the site has brought many surprising discoveries. These included new species of red panda, rhinoceros, pond turtle, hickory tree, and more. The site also hosts the biggest known collection of fossil tapirs.
History
In late May of 2000, this fossil-rich area was discovered during a Tennessee Department of Transportation road construction project on the outside of Gray, TN. As it became clear that the fossils were not usual for this part of the country, members of the local community began an effort to preserve the site.
Many of the fossil fauna and flora of the Gray Fossil Site are closely related to modern-day species in Europe and Asia, including red pandas, European badgers, Chinese moonseed, and Corylopsis. This shows that during the Early Pliocene, North America had a biogeographic link with Eurasia, probably at the easternmost part of Asia.
Fossils
The Gray Fossil Site preserves a collection of preserved fossils. It is the only fossil site in the Appalachian region dating near the boundary between the Miocene and Pliocene Epochs. This offers a unique window into this region at this time.
Fish
All of the fish fossils found at the Gray Fossil Site belong to the family Centrarchidae.
Amphibians
Salamanders. Several taxa have been identified, including Ambystoma, Desmognathus, Notophthalmus, and Plethodon. These are the oldest known members of their families in the Appalachian mountains, a region well-known for its modern salamander diversity. Frogs. Numerous taxa, including Rana.
Reptiles
Alligators. Multiple well-preserved specimens have been identified to the genus Alligator. These appear to be distinct from known alligator species. Lizards. Identified lizards include skinks, anguids, and helodermatids. Snakes. The most common snakes are colubrids, of which multiple species have been identified. This includes the endemic fossil species Zilantophis schuberti. Viperids were also found. Turtles. These are the most diverse group of reptiles at the site, including several taxa of box turtles, painted turtles, slider turtles, snapping turtles, and tortoises. Among these are two species only known from the Gray Site, the musk turtle Sternotherus palaeodorus and the slider turtle Trachemys haugrudi.
Birds
A preliminary study in 2011 identified several families of birds at the Gray Fossil Site, the most common of which were ducks.
Mammals
Perissodactyls (odd-toed hoofed mammals)
Tapirus polkensis (dwarf tapir). The Gray Fossil Site has the largest tapir population of any known fossil site, including fossil tapirs of all ages, from very young juveniles to old adults. Teleoceras aepysoma (rhinoceros). Several specimens are known, including two nearly complete skeletons. In 2019, the Gray Fossil Site rhinos were identified as a new species, named the "high-bodied" Teleoceras for their longer front legs compared to other species. Cormohipparion emslei (three-toed horse)
Artiodactyls (even-toed hoofed mammals)
Peccaries. Two species have been identified: Mylohyus elmorei and Prosthennops serus. Pediomeryx. Camel, possibly Megatylopus
Carnivora
Pristinailurus bristoli (red panda). This was named as a new species in 2004. The two nearly complete skeletons make this one of the best-known fossil pandas. Arctomeles dimolodontus (Eurasian badger). This species was named alongside the Gray Fossil Site panda in 2004. Gulo sudorus (wolverine). The oldest known fossil wolverine. Named the "sweaty wolverine" since the ancient climate of Gray was much warmer than modern wolverine habitats. Plionarctos (short-faced bear). Saber-toothed cat, possibly Machairodus. Buisnictis breviramus (skunk)
Proboscidea (elephants)
Mastodon. Likely a new species. This includes one nearly complete and very large skeleton. Early findings of proboscidean fossils at Gray were originally believed to belong to a gomphothere.