Bones of mammals today might not be uncommon but this unusual fossil is. Before being put on display at the Wyoming State Museum in Cheyenne, an open house for a new mammal fossil discovered near Kemmerer, WY will take place at the Wyoming State Geological Survey (next to the Geological Museum) 9 a.m. to 4 p.m., Sept. 24 through Sept. 28, and from 11 a.m. to 3 p.m. Saturday, Sept. 29.
President and owner of Warfield Fossil Quarries, Rick Hebdon, discovered the fossil in Kemmerer in 2016 on a state leased quarry. Due to its distinction, the fossil was found to be a rare specimen and was turned over to the state of Wyoming following Office of State Lands and Investments fossil permit regulations.
“A bizarre thought, this was a fresh water lake so why are we finding mammals at all? We are used to finding fish by the thousands, to find a mammal is crazy rare. They had to die up stream and float past a gauntlet of crocodiles, turtles, and other flesh-eating animals to even make it to the lake,” Hebdon said.
The late Dr. Greg Gunnell, paleontologist and former director at the Duke Lemur Center, identified Hebdon’s fossil as a tapiromorph. Closely related to rhinoceroses or horses, a tapir is a large, plant-eating mammal despite resembling pigs and anteaters.
Modern tapirs have not changed a lot from their primitive form, so the fossil resembles the modern analogues of baird’s tapir, lowland tapir, mountain tapir, and/or Malayan tapir. The specimen may be a new genus of tapiroid and support a North American origin for tapiroids.
“This fossil is the first of its kind discovered in the Green River Formation. This was a time very early in the evolution of mammals. This fossil represents a whole branch of mammals to come. It makes it possible to answer many questions about the origin of its species,” Hebdon said.
The WSGS hired researcher Mike Eklund to prepare the fossil. To do so, he used special lighting and photography techniques. He conducted his work under a microscope with time-lapse photograph. Videos and photos of his work can be viewed on the WSGS website.
The specimen is missing its upper skull, but the lower jaw and teeth are intact. High-quality preservation of the hind legs and feet are present, along with a front leg and foot. Bones from the hip region are visible, but the ribcage is engulfed with roots and not as well-preserved.
“I have heard there may be plans to temporarily display it at Fossil Butte National Monument so that the locals from Kemmerer can come see what came from their own backyard,” said Hebdon. After being displayed at the Wyoming State Museum in Cheyenne through winter the last day the public can see the fossil on display at WSGS is Saturday, Sept. 29 from 11 a.m. to 3 p.m.
