Gray Fossil Site

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.

Rodents

- Several species, including beavers, packrats, and mice.

Lagomorphs

- Two species of extinct rabbits.

Bats

- Two species of vespertilionid bats.

Eulipotyphla
- Several species of shrews and moles.
Xenarthra

- An unknown species of megalonychid sloth.

### Invertebrates

Aquatic invertebrates of the Gray Fossil Site include ostracods, snails, and small clams. Insects are also known from fossilized exoskeletal remains and trace fossils, including at least four different families of beetles.

### Plants

Plant fossils at the Gray Fossil Site include pollen, leaves, wood, fruits, seeds, and other structures which represent a diverse flora of angiosperms, conifers, ferns, lycophytes, and bryophytes. The forest flora was dominated by a variety of trees and shrubs, of which the most common were hickory, oak, and pine.

Several previously unknown extinct plant species have been identified at the Gray Fossil Site:

- _Carya tennesseensis_ (hickory)
- _Sinomenium macrocarpum_ (moonseed)
- _Staphylea levisemia_ (bladdernut)
- Three species of _Vitis_ (grapes)
- _Corylopsis grisea_ (witch hazel)
- _Cavilignum pratchettii,_ the first extinct genus of plant identified at the Gray Fossil Site.

### Algae

Algal microfossils have been identified as numerous freshwater species, including one previously unknown extinct species, _Stigmozygodites grayensis,_ named from the Gray Fossil Site in 2013.

### Fungi

Several types of fungi have been found from microfossil remains of fungal tissue and fruiting bodies.