I had something similar happen to me. I was out walking my dinosaur and we found some dog bones.
How do they know it was a 70 million year old dinosaur fossil? Well, it was in a 70 million year old rock. Well, how do they know it was a 70 million year old rock? Well, because it had a 70 million year old dinosaur fossil in it. See how this goes?
Was it the dinosaur’s leftovers?