Pachycephalosaurus

"''A Pachy... a pachy... oh, hell. Uh, the fathead with the bald spot. Friar Tuck!" - Roland Tembo'' Pachycephalosaurus was a medium-sized herbivorous dinosaur that lived in the late Cretaceous period, 75 to 65 million years ago, in North America. They are famous as "bone-head" dinosaurs, due to the 10-inch thick rounded plate of bone in their foreheads. Contrary to popular belief, Pachycephalosaurus probably did not butt heads with each other.

Diet
Scientists do not yet know what these dinosaurs ate. Having very small, ridged teeth they could not have chewed tough, fibrous plants as effectively as other dinosaurs of the same period. It is assumed that pachycephalosaurs lived on a mixed diet of leaves, seeds, fruits. The sharp, serrated teeth would have been very effective for shredding plants.

In The Lost World: Jurassic Park
Pachycephalosaurus was seen ramming into hunters and equipment. They were, however, only half the size of their real life counterparts, that were about 8 meters long. A possible explanation was that these individuals were not fully grown. Roland had nicknamed them "Friar Tuck", as he could not pronounce their real name.

The Herd
King Came around a corner, and saw a herd of animals in the road. They were some kind of green dinosaur, about 4ft tall, with big domed heads and a bunch of little horns, that smooth bulging curve on the forehead and all those little horns. The front bumper nudged the nearest animal, which grunted, took a couple of steps back, lowered it's head and butted the front of of the car with a metallic clang! He opened the door, and climbed out, the animals jumped to their feet and the nearest one charged him. He had the door open; the animal smashed into it, slamming it shut, leaving a deep dent in the metal. He ran around the back of the car, just as another smashed into the rear taillight, shattering the plastic. A third animal charged the back of the car directly. King scrambled up onto the spare tire, as it slammed into the bumper. The jolt knocked him off, and he fell to the ground, rolling while the Pachycephalosaurus snorted all around him.

Dodgson
"Is Levine there?" The radio clicked. Harding said, "Ask him if there's any danger from a green dinosaur that's about 4 ft tall and has a domed forehead." Levine nodded. "Tell her yes. They're called Pachycephalosaurus" "Why?" "Because there's about 50 of them all around the car."

Explorer
Now the puddle had become a mudhole, thanks to the dozen or so animals that sat in it. These were the green dome-headed that she had been watching. She had watched the Pachycephalosaurus with uneasiness. "Levine says nobody knows anything about these animals, Sarah" "Great," she said. "Levine says a complete skeleton has never been recovered. So nobody has even a guess about their behavior, except that they're probably aggressive."

Suddenly one of the animals charged the trunk of the tree she was in, butting it hard. The impact was suprisingly forcefull. She struggled to hold on. Oh shit, she thought. Then she hit the ground, right beside the animals.

Sarah Harding was underneath the car, and now she was staring out at the animals feet. The pachys were stamping and snorting, Trying to get at her under the car. The nearest pachys snorted and banged on the bumper. They leaned down and twisted their heads, trying to get to her. "They have very bad breath," she said. Suddenly, they all thundered off.

In Jurassic Park (SNES game)
Pachycephalosaurus is depicted to be territorial, meaning that they will attack if the player/other dinosaurs were inside their territory. They're not a strong enemy as they can be easily killed.

In The Lost World: Jurassic Park (arcade game)
In this game, you will be sitting in your car, and a bunch of Pachycephalosaurus will charge you. In order to defeat them, you will have to shoot their body, shooting their bone-head wouldn't be affective.

In The Lost World: Jurassic Park (console game)
Pachycephalosaurus is encountered in the Human Hunter and velociraptor levels. The Pachycephalosaurus is bigger than the ones seen in the film, furthermore suggesting that they were not fully grown in the film. Like in the arcade game they can only be hurt if hurt/shot in the body.

In Warpath: Jurassic Park
Pachycephalosaurus is playable.

In Operation Genesis
Pachycephalosaurus is a two-star small herbivore, at closer to its correct length than those of the movie. It is the primary dinosaur that the player must create to endorse more new dinosaurs. It will fight against each other, although they never seriously injure each other. They also use their hard heads to attack small carnivores. They are friends of Homalocephale.