Gray Fossil Site

Exhibits at the Gray Fossil Site & Museum, including replicas of fossil tapirs, alligator, and rhinoceros

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

Gray Fossil Site & Museum during the Grand Opening in 2007.

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.^[1][2]

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.^[3]

Fish

All of the fish fossils found at the Gray Fossil Site belong to the family Centrarchidae.^[4]

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.^[5]
• Frogs. Numerous taxa, including Rana.^[3]

Fossil shell of Chrysemys (painted turtle) from the Gray Fossil Site.

Reptiles

• Alligators. Multiple well-preserved specimens have been identified to the genus Alligator. These appear to be distinct from known alligator species.^[6]
• Lizards. Identified lizards include skinks, anguids, and helodermatids.^[3]
• 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.^[3]
• 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.^[7] Among these are two species only known from the Gray Site, the musk turtle Sternotherus palaeodorus^[8] and the slider turtle Trachemys haugrudi.^[7]

Birds

A preliminary study in 2011 identified several families of birds at the Gray Fossil Site, the most common of which were ducks.^[9]

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.^[10]
• 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.^[11][12]
• Cormohipparion emslei (three-toed horse)^[13]

Artiodactyls (even-toed hoofed mammals)

• Peccaries. Two species have been identified: Mylohyus elmorei and Prosthennops serus.^[14]
• Pediomeryx.^[15]
• Camel, possibly Megatylopus^[13]

Fossil skull of Pristinailurus bristoli, Gray Fossil Site red panda.

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.^[16]
• Arctomeles dimolodontus (Eurasian badger). This species was named alongside the Gray Fossil Site panda in 2004.^[17]
• 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.^[15]
• Plionarctos (short-faced bear).^[13]
• Saber-toothed cat, possibly Machairodus.^[13]
• Buisnictis breviramus (skunk)^[15]

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.^[18]

Rodents

• Several species, including beavers, packrats, and mice.^[15]

Lagomorphs

• Two species of extinct rabbits.^[15]

Bats

• Two species of vespertilionid bats.^[19]

Eulipotyphla

• Several species of shrews and moles.^[13]

Xenarthra

• An unknown species of megalonychid sloth.^[13]

Invertebrates

Aquatic invertebrates of the Gray Fossil Site include ostracods, snails, and small clams.^[20] Insects are also known from fossilized exoskeletal remains and trace fossils, including at least four different families of beetles.^[21]

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.^[22][23] The forest flora was dominated by a variety of trees and shrubs, of which the most common were hickory, oak, and pine.^[22][24]

Several previously unknown extinct plant species have been identified at the Gray Fossil Site:^[22][24]

• 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.^[23]

Fungi

Several types of fungi have been found from microfossil remains of fungal tissue and fruiting bodies.^[25]

References

1. Whitelaw, Michael J.; Shunk, Aaron; Liutkus, Cynthia M. (2011). "Formation, structure, and fill of the Gray Fossil Site Basin". Schubert BS, Mead JI, Eds. Gray Fossil Site: 10 Years of Research.
2. "History | ETSU Gray Fossil Site and Museum". www.etmnh.org. Retrieved 2021-01-21.
3. Jasinski, Steven E.; Moscato, David A. (2017-06-01). "Late Hemphillian Colubrid Snakes (Serpentes, Colubridae) from the Gray Fossil Site of Northeastern Tennessee". Journal of Herpetology. 51 (2): 245–257. doi:10.1670/16-020. ISSN 0022-1511. S2CID 90960539.
4. Woodward, Brett (2011). "Fishes of the Mio-Pliocene Gray Fossil Site". Schubert BS, Mead JI, Eds. Gray Fossil Site. 10 Years of Research: 93–95.
5. Boardman, Grant S.; Schubert, Blaine W. (2011). "First Mio-Pliocene salamander fossil assemblage from the southern Appalachians". Palaeontologia Electronica. 14.
6. Schubert, Blaine W.; Mead, Jim I. (2011). "Alligators from the Gray Fossil Site". Schubert BS, Mead JI, Eds. Gray Fossil Site. 10 Years of Research: 61–64.
7. Jasinski, Steven E. (2018-02-13). "A new slider turtle (Testudines: Emydidae: Deirochelyinae: Trachemys) from the late Hemphillian (late Miocene/early Pliocene) of eastern Tennessee and the evolution of the deirochelyines". PeerJ. 6: e4338. doi:10.7717/peerj.4338. ISSN 2167-8359. PMC 5815335. PMID 29456887.
8. Bourque, Jason R.; Schubert, Blaine W. (2015-01-02). "Fossil musk turtles (Kinosternidae, Sternotherus) from the later Miocene–early Pliocene (Hemphillian) of Tennessee and Florida". Journal of Vertebrate Paleontology. 35 (1): e885441. doi:10.1080/02724634.2014.885441. ISSN 0272-4634. S2CID 86840420.
9. Steadman, David W. (2011). "A Preliminary Look at Fossil Birds from the Gray Fossil Site, Tennessee". Schubert BS, Mead JI, Eds. Gray Fossil Site. 10 Years of Research: 73.
10. Schap, Julia A.; Samuels, Joshua X. (2020-05-26). "Mesowear Analysis of the Tapirus polkensis population from the Gray Fossil Site, Tennessee, USA". Palaeontologia Electronica. 23 (2): 1–16. doi:10.26879/875. ISSN 1094-8074.
11. Short, Rachel; Emmert, Laura (2019). "A new species of Teleoceras (Mammalia, Rhinocerotidae) from the Late Hemphillian of Tennessee" (PDF). Bulletin of the Florida Museum of Natural History. 56: 183–260 – via Florida Museum of Natural History.
12. "A new species of rhino". www.etsu.edu. Archived from the original on 2019-05-16. Retrieved 2021-01-19.
13. Schubert, Blaine W (2011). "History of the Gray Fossil Site and the Don Sundquist Center of Excellence in Paleontology". Schubert BS, Mead JI, Eds. Gray Fossil Site. 10 Years of Research: 1–6.
14. Doughty, Evan M.; Wallace, Steven C.; Schubert, Blaine W.; Lyon, Lauren M. (2018-11-30). "First occurrence of the enigmatic peccaries Mylohyus elmorei and Prosthennops serus from the Appalachians: latest Hemphillian to Early Blancan of Gray Fossil Site, Tennessee". PeerJ. 6: e5926. doi:10.7717/peerj.5926. ISSN 2167-8359. PMC 6276594. PMID 30533292.
15. Samuels, Joshua X.; Bredehoeft, Keila E.; Wallace, Steven C. (2018-04-18). "A new species of Gulo from the Early Pliocene Gray Fossil Site (Eastern United States); rethinking the evolution of wolverines". PeerJ. 6: e4648. doi:10.7717/peerj.4648. ISSN 2167-8359. PMC 5910791. PMID 29682423.
16. Fulwood, Ethan L.; Wallace, Steven C. (2015-09-01). "Evidence for unusual size dimorphism in a fossil ailurid". Palaeontologia Electronica. 18 (3): 1–6. doi:10.26879/526. ISSN 1094-8074.
17. Wallace, Steven C.; Wang, Xiaoming (September 2004). "Two new carnivores from an unusual late Tertiary forest biota in eastern North America". Nature. 431 (7008): 556–559. Bibcode:2004Natur.431..556W. doi:10.1038/nature02819. ISSN 1476-4687. PMID 15457257. S2CID 4432191.
18. "Elephantine undertaking: Digging up a giant mastodon | Fossils | Earth Touch News". Earth Touch News Network. Retrieved 2021-01-19.
19. Czaplewski, Nicholas J. (2017-04-27). "First report of bats (Mammalia: Chiroptera) from the Gray Fossil Site (late Miocene or early Pliocene), Tennessee, USA". PeerJ. 5: e3263. doi:10.7717/peerj.3263. ISSN 2167-8359. PMC 5410148. PMID 28462055.
20. "Gray Fossil Site in Tennessee". www.tn.gov. Retrieved 2021-01-16.
21. Doby, Joshua R.; Wallace, Steven C. (2014). "Fossil Insects of the Gray Fossil Site (Hemphillian) Washington County, Tennessee". The Paleontological Society Special Publications. 13: 86–87. doi:10.1017/S2475262200011850. ISSN 2475-2622.
22. Quirk, Zack J.; Hermsen, Elizabeth J. (2020). "Neogene Corylopsis seeds from eastern Tennessee". Journal of Systematics and Evolution. 59 (3): 611–621. doi:10.1111/jse.12571. ISSN 1759-6831.
23. Worobiec, Elzbieta; Liu, Yu-Sheng (Christopher); Zavada, Michael S. (2013). "Palaeoenvironment of Late Neogene lacustrine sediments at the Gray Fossil Site, Tennessee, USA". Annales Societatis Geologorum Poloniae. 83: 51–63.
24. Siegert, Caroline; Hermsen, Elizabeth J. (2020-04-01). "Cavilignum pratchettii gen. et sp. nov., a novel type of fossil endocarp with open locules from the Neogene Gray Fossil Site, Tennessee, USA". Review of Palaeobotany and Palynology. 275: 104174. doi:10.1016/j.revpalbo.2020.104174. ISSN 0034-6667.
25. Worobiec, Grzegorz; Worobiec, Elzbieta; Liu, Christopher (Yusheng) (2018). "Fungal remains from late Neogene deposits at the Gray Fossil Site, Tennessee, USA". Mycosphere. 9 (5): 1014–1024. doi:10.5943/mycosphere/9/5/5.