Pachycephalosaurus was a herbivore that was in the Ornithopod family. It walked on two legs and had a dome head. It was about seven (7) inches deep and had ornate spikes around it. It could run and bang its head against another pachycephalosaur like a ram. It could not have banged its head against the head of another pachycephalosaur because they could crack. Instead, they banged up against the body of the other.