University of Calgary archaeologist Brian Kooyman, geologist and palaeontologist Len Hills and graduate students Paul McNeil and Shayne Tolman made the find after recovering protein residue of the ancient horse from two 11,300-year-old Clovis spearheads found at the site in western Canada.

The scientists are leading a team excavating the dry bed of the St. Mary Reservoir, located 15 km east of Cardston, southern Alberta (just north of the U.S.-Canada border near Montana's Glacier National Park).

The site, now protected under the Alberta Historical Resources Act, is emerging as one of North America's richest archaeological fields and is dated, using the Carbon 14 method, to 11,000-11,300 years.

Since 1998, the U of C team has identified hundreds of well-preserved footprints of woolly mammoths and ancient horses, as well as the first footprints found on Canadian soil of the ancient North American camel, which became extinct almost 10,000 years ago.

The team also has uncovered the skeletons of numerous long-extinct animal species –- including the helmeted musk oxen, bison, wolves, foxes, badgers and ground squirrels.

The link between the Equus conversidens horse and human hunters was established after team members unearthed a skeleton of the extinct horse at the site with several of its vertebrae smashed and what appeared to be butcher marks on a number of its bones.

Some 500 meters from the skeleton, they also discovered several Clovis spearheads. Protein residue testing and examination of the spearheads confirmed the artifacts had been used to hunt the extinct horse.

Although archaeologists have long suspected that the "big game" hunters of the Clovis period (11,500-11,000 years B.P.) hunted the horses, there has been little evidence to support this theory until now.

"In the past, we could really only attribute the demise of these ancient horses to climate and environmental changes," says Kooyman. "This discovery raises the very real possibility that overhunting of these animals by the Clovis people may have played a significant role in their extinction."

Horses were reintroduced to the Americas during the 16th Century by the Spanish Conquistadors, with a number of these animals escaping and quickly establishing large wild populations. It was not until the 19th Century that scientists realized ancient relatives of the modern horse had once roamed the continent but had died out around 10,000 years before, at the end of the Pleistocene Era, or Ice Age.

The U of C team has been astounded by the wide selection of ancient animal footprints present on the river floodplain –- providing them with one of the last "snapshots" of the late Pleistocene Era, recorded shortly before many of these species became extinct.

"You normally don't find the tracks of so many ancient animals together in the same place at the same time or in association with humans," says Hills. "It gives us a wonderful picture of what was going on back then."

As the animals traveled from this grazing area to the river for water, they left behind footprints in the mud. While such prints would disappear within a few days under normal conditions, strong winds in the area deposited sand and silt in the impressions, preserving them in near-perfect condition

In 1949, the St. Mary Reservoir was built over the site -- its architects unaware of the archaeological significance of the area. The importance of the site was first recognized in 1998 by Cardston elementary teacher Shayne Tolman, who was visiting the area with his family after it had been drained to allow construction of a new spillway. After discovering numerous Clovis spearheads and other artifacts, Tolman alerted local archaeologist Barry Wood to the find, then contacted Hills and Kooyman.

After initial examination, Kooyman and Hills returned to the site with palaeontology graduate student Paul McNeil to assess its full potential. During this period, numerous tracks and trackways were discovered, as were additional faunal remains.

With the reservoir due to be filled again by the summer rains, the scientists are now working against time to document and preserve their discoveries.

"This site is one of the best preserved areas of ancient animal tracks in North America –- possibly the world," says Kooyman. "It's providing us with an astonishingly detailed picture of what the New World was like during the late Pleistocene Era. We can't believe how lucky we are."

[Contact: Dennis Urquhart ]

03-May-2001