Last Thursday, the Denver Museum of Nature and Science (DMNS) wrapped up its largest-ever fossil excavation in Snowmass Village, Colo., uncovering a record-breaking number of more than 4,000 Ice Age fossils. The dig spanned a total of 69 days, beginning in October 2010, and uncovered a total of 4,826 bones. Students and volunteers worked alongside scientists to excavate the fossils in the dig, which was dubbed The Snowmastodon Project by the DMNS.
The dig began shortly after Jesse Steele, a bulldozer driver in Snowmass Village, inadvertently discovered the fossilized bones of a young Columbian mammoth while working on an expansion of the Ziegler Reservoir. The town of Snowmass Village donated the fossils to the Denver museum, which then began an intense full-scale excavation to remove the Pleistocene-era fossils from an Ice Age lakebed in the Ziegler Reservoir. The Pleistocene era spans the epoch from 2.5 million to 12,000 years before present day. Snowmass Village is a small town about 200 miles west of Denver with a population of about 1,800, and is a favored location for skiers and snowboarders. The discoveries have excited the town’s residents, who clamored to view the ancient bones at an event hosted by the museum in June.
Among the species uncovered in the dig are 26 vertebrate animals: 7 large mammals and 19 small animals, including Columbian mammoths, over 30 young and old American mastodons, horses, giant bison, fish, birds, amphibians, reptiles, small mammals and several new species. The discovery of the horse is particularly significant, as horses native to North America vanished from the continent 12,000 years ago. The dig uncovered the first-ever mastodon skulls to be found in Colorado. The Columbian mammoth was an herbivore and one of the largest-ever species of elephants, growing to a height of 13 feet (4 meters) and weighing in at 10 metric tons. The furry American mastodon, distantly related to the mammoth, stood at 10 feet (3 meters) tall and weighed 6 tons. Both animals had long, curved tusks, with mammoth tusks measuring 6.5 feet (2 meters) and mastodon tusks measuring 16 feet (5 meters).
Plant material was also unearthed at the site, including wood, rocks, leaves, peat and 125 logs. A team of 55 scientists from the United States, Canada, England and Spain sought to understand the lake’s history, climate and ecology by sampling several layers of sediment from the depths of the lakebed. Carbon dating places the Ziegler Reservoir site as at least 45,000 years old, but possibly up to 150,000 years old.
These fragile fossils were buried under layers of peat and silt, whose moisture has preserved them for tens of thousands of years. The DMNS has taken special care to ensure that they do not dry out too quickly and deteriorate. For some fossils, the careful drying process will take months.
A family event is planned at the museum for July 23 and 24, in which visitors can view the newly-revealed fossils and learn more about their history with games and an interactive show. Visitors can also see the fossils being prepared up close in the museum’s laboratory and can touch fossils such as mastodon and mammoth teeth. The DMNS plans to open a touring exhibit called Mammoths & Mastodons: Titans of the Ice Age in Spring 2013, which will contain fossils from the excavation as well as other fossils, including a 42,000 year old mammoth that is considered the most well preserved in history. Now that the dig has concluded, the expansion of the Ziegler Reservoir will continue, with the added presence of museum staff on-site to claim any potential fossils uncovered during this time.
Photo credit: flickr.com/photos/dokidoki/5716379653/