According to the Lansing State Journal, Harding says the remnant is the top portion of a tooth from the giant elephant-like mastodon which probably got stuck in a swamp and drowned thousands of years ago.
Phillip has been nicknamed "Huckleberry Phil" in his neighborhood for his love of exploring the outdoors barefoot. He tells CNN the discovery has inspired him to follow his dream of becoming a paleontologist.
Now the fossil is used in the Stoll household to teach Phillip's six siblings about the ancient creatures during their homeschooling. (Via HLN)
Harding says in Michigan Mastodon remnants emerge about every three to four years.
Back in 2012, two 11-year-old boys found a 13,000-year-old mastodon axis bone while fishing for crayfish in a stream near their homes. (Via The Advisor & Source)