Lesson 3. What does the fossil assemblage tell us about the paleoenvironment at the Gray Fossil Site? 


In order to understand what the overall habitat was like in Gray TN during the early Pliocene, we need to look for similarities in the habitat requirements of the animals that lived there. As a class, you will create a master chart that tracks the habitat requirements of the six main animals you've researched. 

Gray Paleo-Habitat Reconstruction

As a class, use the worksheet below, or create a Jam Board table, to compare the habitat requirements for the six species we investigated from the Gray Fossil Site. Look for similarities between the habitat needs of the species, and try to decide what those requirements tell us about the paleo environment from the site. For instance, did the site have trees or was it open? Did it have any water or was it a dry environment? Can you tell if the winters were warm or cold?

Once you’ve finalized your conclusions about the paleo environment, click the tab below to learn about the paleo-habitat reconstruction created by the paleontologists who work at the site. How close were your conclusions to those of the scientists? 

Paleo-Habitat Reconstruction Check

An artist's reconstruction of the paleo-habitat at the Gray Fossil Site

Despite overall cooling since the extinction of the dinosaurs, 65 million years ago, scientists know that the Pliocene epoch (5.4 to 2.4 million years ago) was still somewhat warmer than the present based on analyses of deep ocean sediment cores. Sediments dating to the Pliocene contain more thermophilic (warm-loving) plankton than younger sediments. 

But how does this translate to the Gray Fossil Site in northeastern Tennessee? Although there are no plankton in Gray Fossil Site sediments, the presence of large reptiles such as alligators and gopher tortoises indicate that the winters were not as cold, and that the average annual temperature was warmer than it is today. 

Many of the plant species found at Gray are similar to those that can be found in modern Tennessee backyards. Deciduous trees like oak, hickory, and elm are present as pollen grains in Gray Fossil Site sediments, and sometimes as wood fragments in the sinkhole itself. Many of the animals are also forest dwellers. Modern relatives of tapirs and red pandas are found only in very dense forests suggesting that these environments surrounded the Gray sinkhole.