Eric Stamatin, 11, of Shelby Township, and his cousin, Andrew Gainariu, also 11, of Troy, found a mastodon bone over the summer while exploring in Eric's backyard near a stream in the 24 Mile and Dequindre area.
"At first it just looked like a rock, but it had a hole in it so we thought maybe it was a bone," Eric told the Detroit News.
A research scientist with the Cranbrook Institute of Science in Bloomfield Hills confirmed the fossil the boys stumbled across was an axis bone of the extinct American mastodon.
Mastodons were furry elephant-like mammals that became extinct in North America about 10,000 years ago. They are relatives of the wooly mammoth.
The axis bone is one of two specialized vertebrae that secure the head to the vertebral column, said John Zawiskie, a paleontologist at Cranbrook and adjunct geology professor at Wayne State University.
