The long-standing Clovis model said that Clovis people first populated North America 13,000 years ago. A new archaeological finding now suggests we need to move on from this old theory.

A mastodon rib bone dates back 13,800 years ago. This is believed to be a hunting weapon of the people that used it. Mastodons were large tusked mammals that appeared much like elephants. Scientists believe the first North American inhabitants hunted these large beasts in the pre-Clovis era.

The piece of evidence was discovered over 30 years ago at a site in Sequim, Washington by a Washington State University archaeologist. Since then, carbon dating and reinvestigation have confirmed that it was a hunting tool.

Michael Waters from Texas A&M looked at the specimen with his colleagues again. They concluded that the bone is at least 800 years before original Clovis artifacts. DNA investigation also confirmed that the bone point itself came from mastodon bone too. More importantly, this shift in timing ultimately suggests that human inhabitants may have something to do with animal extinctions at the end of the final Ice Age.

There remains great controversy over the explanations for global extinction, but being precise about human presence relative to the animals' will play a key role in uncovering the mystery. The research results were published in Science.