The skull was short, and possessed large, rounded eye sockets that faced forward, suggesting that the animal had good eyesight and was capable of binocular vision. "Pachycephalosaurus" had a small muzzle which ended in a pointed beak. The teeth were tiny, with leaf-shaped crowns. The head was supported by an "S"- or "U"-shaped neck. Younger individuals of "Pachycephalosaurus" maybe have had flatter skulls, with larger horns projecting from the back of the skull. As the animal grew, the horns shrunk and rounded out, as the dome grew.