A theory put forth by a group of 25 geo-scientists suggests that a massive comet exploded over Canada, possibly wiping out both beast and man around 12,900 years ago, and pushing the earth into another ice age.

University of South Carolina archaeologist Dr. Albert Goodyear said the theory may not be such "out-of-this-world" thinking based on his study of ancient stone-tool artifacts he and his team have excavated from the Topper dig site in Allendale, as well as ones found in Georgia, North Carolina and Virginia.

Archaeologists have long known that the great beasts of the age – the wooly mammoth and mastodon – suddenly disappeared around the same time period (12,900 - 12, 800 years ), but little was known about their demise. It was thought to be the result of over-hunting by Clovis man or climate change associated with a new ice age.