Pictures: "Remarkable" Ice Age Fossil Cache Found

"Cool" Ice Age Skull
Photograph courtesy Heather Rousseau, Denver Museum of Nature & Science
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. (See "Comet "Shower" Killed Ice Age Mammals?")
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.
Published February 9, 2011
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."
(See a National Geographic magazine interactive on bringing mammoths back to life.)
Published February 9, 2011
Fossils in Waiting
Photograph courtesy Rick Wicker, Denver Museum of Nature & Science
Fossils recovered from the Ice Age site sit in the Denver Museum of Nature & Science's conservation lab in an undated picture. The Ice Age cache is unusual because of its high altitude and the diversity of animals, plants, and insects that have accumulated there over the millennia, experts say.
High-altitude sites are "consistently underrepresented" in the Ice Age fossil record, said Daniel Fisher, a mastodon expert at the University of Michigan. (Related picture: "Oldest Art in Americas Found on Mammoth Bone?")
"There have been suggestions that high-altitude environments might have harbored different communities, or had a different story of change, but since fossils representing them are so rarely found, no one has known for sure," Fisher said in a statement.
"Now is our chance to see what they are like."
Published February 9, 2011
Oh, Deer
Photograph courtesy Rick Wicker, Denver Museum of Nature & Science
Museum collections assistant Carol Lucking cleans the jaw of an Ice Age deer found at the Colorado site, as seen on November 12. (See "Extinct Giant Deer Survived Ice Age, Study Says.")
In addition to the large-animal fossils, scientists have also found seeds, pollen, mummified leaves, and fossilized snails dating back to the Ice Age.
Published February 9, 2011
Iconic Find
Photograph courtesy Paul Carrara, USGS
Scientists excavate a mastodon tusk from the Colorado dig site in an undated picture. The Ice Age fossil cache is one of the most significant finds ever made in Colorado, according to the Denver museum.
"Not only will it completely shape our understanding of life in the Rockies during the Ice Age, but it will become forever iconic for the kids of Colorado," chief curator Johnson said. (See picture: "'World's Longest Tusks' Among Greek Mastodon Find.")
Published February 9, 2011
Cleaning a Giant
Photograph courtesy Rick Wicker, Denver Museum of Nature & Science
Museum volunteers clean a mastodon skull in the Denver museum's paleontology lab in November. Drying the bones—which were saturated during excavations—could take a year or longer, according to the museum. If fossils dry too quickly, they could crack and disintegrate.
(See "Mastodons Driven to Extinction by Tuberculosis, Fossils Suggest.")
Published February 9, 2011
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. (Read about resurrecting mammoths in National Geographic magazine.)
Published February 9, 2011