The Rise and Fall of the Dinosaurs: A New History of a Lost World: The Definitive Dinosaur Encyclopedia with Stunning Illustrations, Embark on a Prehistoric Quest!

by Steve Brusatte

The map and bone inventory revealed something peculiar. There were three copies of the same bone: three left nasals, the bone that makes up the front and side of the snout. Each Triceratops had only one left nasal, the same way it had only one head or one brain. Then it dawned on us: we had three Triceratopses: not only Homer, but Bart and Lisa too. Helmuth had found a Triceratops graveyard. It was the first time that anybody had found more than one Triceratops in the same place. Until Helmuth walked into that gully, we thought Triceratops was a solitary animal—and we were fairly confident, because Triceratops was so common, already known from hundreds of fossils found over a hundred years, each one a single individual, encountered on its own. But one discovery can change everything, and because of what Helmuth found, we now think that Triceratops was a pack species.