Gray Fossil Site

Research at the site has yielded many surprising discoveries, including new species of red panda, rhinoceros, pond turtle, hickory tree, and more.

The sinkhole that contains the fossil-rich deposits of the Gray Fossil Site is the result of a series of overlapping collapse events that ultimately formed one large basin.

Sizable boulders deposited within the lake sediments indicate that the edge of the sinkhole once featured high walls or overhangs where chunks of rock could occasionally break off.

In September 2000, Tennessee Governor Don Sundquist announced that the construction project would be moved so the fossil site could be saved and dedicated to research and education.

The university founded the Don Sundquist Center of Excellence in Paleontology and began construction of an on-site museum to house research facilities and educational exhibits.

[6] Plant fossils found at the site, particularly pollen, indicate that the dominant vegetation of the forest was oak, hickory, and pine trees, along with various herbaceous species.

[9] A 2020 study used fossil mammal teeth as a proxy to estimate the ancient climate conditions of the Gray Fossil Site, estimating a mean annual temperature of 16.8 °C, or 62.2 °F (similar to modern-day Atlanta, GA), and an annual precipitation of 1,343mm, or 52.9in (similar to modern-day Tampa, FL), with the minimum temperature of the coldest month reaching 2.6 °C, or 36.7 °F.

[10] These results line up with earlier hypotheses that the site had a warmer and wetter climate than modern East Tennessee based on the presence of warm-climate animals and plants like alligators, tupelo, and Corylopsis.

Exhibits at the Gray Fossil Site & Museum, including replicas of fossil tapirs, alligator, and rhinoceros.
Figure from a scientific paper showing the stratigraphic ranges (distribution through time) of several identified mammals from the Gray Fossil Site. A gray bar highlights the time period during which these mammals overlapped, between 4.9 and 4.5 million years ago.
Stratigraphic ranges of mammals from the Gray Fossil Site. All of these species overlapped between 4.5 and 4.9 million years ago (gray bar). Image from Samuels et al 2018.
Gray Fossil Site & Museum during the Grand Opening in 2007.
Two parts of a fossil turtle shell, the top (carapace) and bottom (plastron).
Fossil shell of Chrysemys (painted turtle) from the Gray Fossil Site.
Fossil skull of Pristinailurus bristoli , Gray Fossil Site red panda.