Julie Meachen hadn’t ever rappelled in and was nervous as she leaned back off the ledge and started her descent into Natural Trap Cave, near Lovell.
The coolness of the cave hit Meachen, an assistant professor of anatomy at Des Moines University, as soon as she left the surface. She landed at the bottom about 90 feet from where she started. It was open and damp. She’d expected to see a mountain of bones, but by that summer in 2014 it looked like things had already been cleared out, from excavations in the 1970s and 1980s.
She wouldn’t find the short faced bear discovered decades before, and saw little remnants of mammoths, despite the discovery of one’s whole skeleton in the 1980s. Instead, she found bones from bison, horses, wolves, coyotes, the American cheetah, as well as rodents and lizards.
More than 1,000 specimens found in summer 2014 are headed to the University of Wyoming this summer. For the past several years they’ve been at other universities, like Georgia Tech, where specialists studied, cleaned and prepared the fossils for storage. UW will continue to receive batches of specimens over the next few years.
The Bureau of Land Management recently named UW a repository for Natural Trap Cave. Repositories have to meet certain standards in security and climate control for storage. The university will store the specimens found at the site and make them available for research, said Laura Vietti, collection manager at the UW Geological Museum.
The new fossils will triple the size of the university’s Pleistocene-era collection, she said.
The collection of specimens found at Natural Trap Cave is incredibly diverse because the cave’s features made it a natural trap, Vietti said. A gentle incline in the landscape hides a 120-foot hole. Running animals — like predators chasing prey — fell into the hole before they realized it was there, she said.
DNA extracted from the cave goes back almost 20,000 years. Meachen and other paleontologists have collected bones not just from big mammals but also from microfauna, including 200 reptiles, Vietti said. The range in species provides good representation of life in the area during that time period, Vietti said.
At the university, the specimens will be curated for research. Eventually information on the collection will be digitized to give access to researchers around the world. The university also will create a Natural Trap Cave display in its museum.
For years, excavations often focused on dinosaurs. But in the past several decades, there’s been a shift to researching Wyoming’s mammals as well, Vietti said.
“Our dinosaurs are fun, but we have a whole bunch of mammals that record this evolution … of mammals from back then into the mammals of today,” she said.
The cave is the only major site open for paleontology work in the state, Brent Breithaupt, regional paleontologist for the BLM said. Because the cave is on BLM land, the agency oversees permitting for work at the site. After work ended in the 1980s, the BLM sealed it and no one visited for 30 years.
“It’s really exciting we’re getting additional work out of this cave,” Breithaupt said. “It can help tell a story about ancient Wyoming and the creatures that lived here.”
Breithaupt first entered the cave more than 30 years ago during a previous research effort. He remembers looking up and thinking about how for animals, there was one way in, and no way out.
“It’s kind of a surreal experience to be in the cave and imagine over the years all these animals have fallen in there and left their remains for paleontologists to find and tell their story,” he said.
Meachen and her collaborators originally set out to look at megafauna and research genetic variation in animals and how it correlated with climate change. The site provided more information than she imagined, including a pollen record that will allow them to understand the flora from thousands of years ago.
There wasn’t a published record of microfauna from previous excavation, so they were also surprised at how much they found, Meachen said. It will help create a more complete picture of the world at that time.
For example, DNA revealed the wolves found in Natural Trap Cave were not the now-extinct dire wolves as was thought, but ancestors of a different subspecies of the living gray wolf, the Beringian wolf found in Alaska and the Yukon. It was the first time the wolf was discovered at mid-latitudes in North America, Meachen said.
This summer marks the start of the last season in the field for Meachen and the other researchers. The site will remain dormant until Meachen or someone else finds funding and applies for a permit for more work. But the data gathered in three years will offer years of analysis and likely yield new discoveries down the road.