The Tyrannosaurus rex and Triceratops horridus known as the dueling dinosaurs were buried together 67 million years ago on a Montana hillside.
“My heart was racing," paleontologist Joe Sertich said. "I realized it was a pretty important dinosaur find."
"That priceless moment when you're driving home from work at 3am and the road is blocked by a 20ft Triceratops!"
It was only about the size of a cocker spaniel, but had an impressive skull.