Carbon-dating teeth suggests two large mammal species roamed ... Previous research has noted other megafauna fossils around 6,000 and 5,000 years old in the American continent and elsewhere ...

A team of researchers spotted two teeth fossils of creatures living alongside dinosaurs who later turned out to be of human ancestors.

"Future paleontologist, Molly, was out searching for fossils on Christmas morning when, what to her wondering eyes appeared…but a huge Megalodon tooth!" the museum wrote on its Facebook page.