Mastodons — elephant-like beasts that lumbered across North America more than 10,000 years ago — are long extinct, but apparently it wasn’t tooth decay that did them in. A 9-year-old Michigan boy stumbled across something — literally — that, it turns out, is a mastodon tooth. “I was walking down at the creek last summer. I felt something that I stepped on so I picked it up and everybody in […]