‘One-stop shopping for the Ice Age’ near Snowmass
May 26, 2011
SNOWMASS VILLAGE – Scientists may run out of superlatives to describe the Ice Age fossil site at Ziegler Reservoir near Snowmass Village, but they’re not running out of bones.New discoveries emerge daily from the soggy goo of what was an ancient lake. Dr. Kirk Johnson, co-leader of the excavation project and chief curator at the Denver Museum of Nature & Science, excitedly pulled one from his pocket Wednesday during a media tour of the dig.The dark, shiny bone is part of the claw of a Jefferson’s ground sloth, a giant grizzly-sized herbivore that had not been documented in Colorado before the first sloth bones were found at the reservoir last fall.”I have no question that if you got too close to one of those sloths, it would immediately rip your face off,” Johnson said. “The specimens are gorgeous,” he added. “This looks like it fell off a sloth last Tuesday.”About two acres of the reservoir, where construction of an earthen dam is scheduled to begin in July, is ground zero at the dig. A rotating crew of 40 people armed with shovels is busy moving tons of mud, uncovering “bone beds” where giant pieces of different animals are haphazardly scattered where they ultimately came to rest as many as 150,000 years ago. More than 100 have already been recovered this spring.In one trench, pink flags mark the outline of a mastodon tusk, lower jaw bone and skull. Nearby are rib bones, and the horn of an Ice Age bison. They were all found in the deepest layer of the former lake, dating back 130,000 to 150,000 years. Scientists believe the shallowest layer is about 50,000 years old. There, bones from at least three mammoths await the attention of paleontologists and volunteers.While the wet earth yields porous bones, the peat and mud itself is being sampled for plant material and pollen grains that will allow experts to trace the evolution of the vegetation during the life of the lake and draw conclusions about climatic conditions.”The big prize, believe it or not, scientifically, from this lake may not be the mammoths and mastodons,” Johnson said. “This lake may give us the first good climate picture in the Rocky Mountains.”I call the place one-stop shopping for the Ice Age. This place actually has it all.”Though no evidence of humans has been found at Ziegler Reservoir (the site is older than the oldest documented humans in North America, about 15,000 years ago), it has produced bones from about 30 different animals in all, and some bones that have yet to be identified.”Oh man, this is as good as it gets,” said Dr. Ian Miller, the Denver museum’s curator of paleontology and co-leader at the dig site. “You can go an entire career and never do something like this.”The first bones, from a juvenile Columbian mammoth, were uncovered in late October by a bulldozer operator while work was under way to enlarge the reservoir, owned by the Snowmass Water and Sanitation District. What was initially thought to be an isolated discovery quickly escalated, and crews removed roughly 600 bones and bone pieces from various animals in two weeks last fall before winter descended in earnest.”I’ve been thinking about this day and night since last November,” Miller confessed.This year’s efforts will involve 36 scientists from 15 institutions and four countries, along with the shovel crews.Despite all manner of spring weather, Johnson said he’s confident the search will cover all of the targeted ground by July 1, when the fossil dig is scheduled to wrap up and dam construction is to begin. A small crew from the museum will remain, however, in case something else pops up.”It’s not as if, if we find a saber-toothed cat in the last two hours of the dig, we have to leave it,” he said.All of the bones will be carefully preserved at the museum, Johnson said, and some could return to Snowmass for an exhibit if the town decided to build a facility to show off its new claim to fame.Study of the bones, and piecing together the story of the site, he said, will continue long after the reservoir is refilled with water, presumably sometime this fall.Two labs are working to extract DNA samples from some of the bones, which could provide new insight into the evolution of a species – from mastodon and mammoth to present-day elephants, for example.The well-preserved bones retain organic material – “they actually still stink,” Miller said. “The DNA people are psyched when bones smell.”In Japan, Miller noted, scientists have vowed to clone a woolly mammoth in the next five years, using DNA extracted from preserved corpses found in Siberia and inserting it into the eggs of African elephants that have had their DNA removed.”Pleistocene Park may be a reality,” he firstname.lastname@example.org
The Crown family, owners of the Aspen Skiing Co., together with the Skico Family Fund, have donated $100,000 to the Snowmastodon Fund, established to help finance the ongoing fossil dig near Snowmass Village.The fund, held by the Aspen Community Foundation, was established by the Denver Museum of Nature & Science, the town of Snowmass Village and Snowmass Water and Sanitation District to cover the immediate costs of the fossil excavation.With the donation, the museum has raised $460,000 toward its $1 million goal.The fundraising effort is critical to finance the cost of the dig, the preservation and storage of the specimens, and educational outreach by the museum, according to Dr. Kirk Johnson, chief curator at the museum. The scale of the Snowmass project is a huge undertaking for the institution, he said.