Pachycephalosaurus has a big, thick dome on its head, and it's got some little bumps on the back of its head, and it's got a bunch of gnarly things on the end of its nose.
El Paquicefalosaure té una protuberància gran i gruixuda al cap, i té alguns petits bonys a la part del darrera del cap, i té una colla de nòduls al final del nas.