Pachycephalosaurus, << `pak` uh SEHF uh luh `sawr` uhs, >> was a plant-eating dinosaur that had a remarkably thick skull. The name Pachycephalosaurus comes from Greek words meaning thick, head, and lizard.
Pachycephalosaurus had a bulky body with short forelimbs and long legs. It probably weighed over 1 ton (0.9 metric ton) and measured 13 to 26 feet (4 to 8 meters) in length. The dinosaur most likely traveled on its hind legs. When moving, Pachycephalosaurus may have carried its body parallel to the ground. A network of bony tendons held aloft its heavy, rigid tail.
Pachycephalosaurus’s thick head was domed over the braincase. The top of its skull measured up to 10 inches (25 centimeters) thick, and bony knobs covered portions of the skull. The animal may have used its thick dome in butting contests for mates or territory. Pachycephalosaurus also had a narrow snout topped by short spikes, possibly for digging up plants. Its small, ridged teeth were not strong, and the animal probably ate fruits, leaves, and seeds. A keen sense of smell and large eyes helped it detect approaching predators.
Pachycephalosaurus lived about 68 million to 65 million years ago, during the last part of the Cretaceous Period. Scientists have found the dinosaur’s remains in western North America.
