"Remarkable" Ice Age Fossil Cache Found

Scientists unearth an Ice Age bison skull near Snowmass Village, Colorado, on November 6.

"I'm trying to think of a cooler fossil that I've even seen in my life," dig team member Kirk Johnson, chief curator at the Denver Museum of Nature & Science, said in a statement.

The bison skull is part of a "bumper crop" of Ice Age animals recently discovered at the site, including American mastodons, Columbian mammoths, tiger salamanders, and a Jefferson's ground sloth—the first ever found in Colorado, according to the Denver museum. Construction workers stumbled upon the Ice Age treasure trove in October while working on a reservoir-expansion project.

While winter weather has put a hold on excavations at the site, scientists are analyzing many of the 600 fossils found so far—thought to date to at least 130,000 years ago—at the Denver museum's laboratory.

Team member Scott Elias, a paleoecologist at Royal Holloway, University of London, also announced in January that he has extracted beetles and other insects from peat samples taken from the site.



Baby Mammoth

Photograph courtesy Rick Wicker, Denver Museum of Nature & Science

The partially excavated fossils of a young Columbian mammoth emerge from the dig site, as seen on November 12. The Colorado fossil cache is one of the few in the United States—and the only one in Colorado—in which mammoth and mastodon fossils have been found together.

Though the two ancient elephant relatives looked similar, there were distinctions. For one, mastodons were smaller than mammoths, had straighter tusks, and they browsed on trees and shrubs. Mammoths were larger than modern elephants and ate mostly grasses. Both giants went extinct about 12,800 years ago, scientists say.

"Sites like this are extremely rare," team member Elias said in a statement. "To find hundreds of bones like this, spanning possibly 100,000 years of time, is a once-in-a-lifetime opportunity."



Well-Preserved Teeth

Photograph courtesy Heather Rousseau, Denver Museum of Nature & Science

The jaw bone and teeth of an Ice Age deer from the Colorado dig are seen in detail on November 6.

The fossils at the site are exceptionally preserved, according to the Denver museum. There's also a "good chance" of recovering ancient DNA from some of the fossils.