Researcher Prepares Largest Fossilized Mammal Found In Green River Formation For Science

May 2, 2018

The largest fossil of a mammal ever found in the Green River formation is getting ready for further research. The ancient fossil was found damaged and in several parts back in 2016 in the 50-million-year old formation.

It’s been identified as in the tapiromorph family. The actual species is still debated, though a Duke University paleontologist identified it as a Heptodon calciculus. 

While the specimen is the largest found in the Green River Formation, Andrea Loveland, a geologist with the Wyoming State Geological Survey, said it holds another distinction. 

“This one, in particular, was found from an older unit then has ever been found before. So, It might be one of the oldest tapiromorphs,” she said.

Mike Eklund, a researcher in Illinois, is now using a microscope and time-lapse photography to learn more about the specific details in the bones and detect soft tissue fossilization. Loveland explained why discovering soft tissue is particularly important.

“It can tell us more. If you have soft tissue, it can really shed light on the life and death of the creature,” she said.

Loveland added fossilized soft tissue is often rare to find given it biodegrades faster than bones and teeth. After the fossil is prepared, it will be housed at Wyoming’s Geological Survey in Laramie for further research and display. The WSGS will update the fossil’s progression on social media.

EDITOR'S NOTE: The story incorrectly stated the fossilized mammal was the size of a rhino, though tapiromorphs are simply related to the mammal. Horses and rhinos are also not in the tapiromorph family.