Pachycephalosaurus is the last, largest, and most famous member of the Pachycephalosauria, or thick-headed dinosaurs. Some Paleontologists include Stygimoloch and Dracorex as subadult and juvenile members of this genus respectively.

Name Meaning

The name means "thick headed lizard," from Greek pachys-/παχυς- "thick", kephale/κεφαλη "head" and sauros/σαυρος "lizard") is a genus of pachycephalosaurid dinosaurs. The type species, P. wyomingensis, is the only known species.

Appearance and Size

In Isla Sorna the Pachycephalosaurus was shown to be youngster. The youngster have shown to be dark grey.

This dinosaur shown to be the size near 6 feet fall and could weigh over 990 lbs. Pachycephalosaurus can reach 15 feet in length.

Their skin was dark brown with dark blue markings.

Habitat: these animals are located over a vast area of Isla Sorna, they were located around forests bordering the plains of Punto Alto, Palo blanco and La Pradera. They love the Upland forests of Mountain Ranges or the Southern Highlands. but will make do with scattered brush elsewhere. they can found in scrublands, plains, forest, riversides, plains, game trails and foothills of mountains and volcanoes. On Isla Nublar they were last seen in the West Plains and Pachy Arena.


In the 1970s paleontologist Peter Galton proposed that male pachycephalosaurs used their dome heads as battering rams, like Bighorn sheep. The idea caught the public's imagination. In The Lost World: Jurassic Park, you can even see the dome-headed pachycephalosaurs doing head butts (of course, these are genetically engineered dinosaurs and not necessarily exactly the same ones that lived 70 million years ago!). But by the 1990s, scientists began to question Galton's head butting theory. It was pointed out that animals who do butt heads have a wide surface area where the heads come into contact to prevent "head slippage." This happens when two animals butt heads at high speed and do not hit straight on. The risk breaking their necks when their heads suddenly snap to one side. Pachycephalosaurus has a domed, or rounded, head, which would minimize surface contact and therefore increase the risk of head slippage. This throws doubt on the idea of any high speed head-butting between pachycephalosaurs, but it does not exclude "head-pushing" of "head-ramming" against non-pachycephalosaurs.


Pachycephalosaurus was created by InGen inside their compound on Isla Sorna where they were taken care of by the workers there at a young age.


It was not planned for InGen's Jurassic Park on Isla Nublar. Only 9 Pachycephalosaurus were cloned.

Wild on Isla Sorna

When Hurricane Clarissa hit Isla Sorna, the InGen workers evacuated the island. The Pachycephalosaurus were either freed by the fleeing workers or broke free themselves. From this point on the Pachycephalosaurus and many of InGen's dinosaurs integrated themselves into Isla Sorna's ecosystem. To fight the Lysine contingency, they would eat Lysine rich plants.

Pachycephalosaurus was known to have lived in the island's south.

Isla Sorna Incident (1997)


The InGen Hunters captured a Pachycephalosaurus on the Game Trail. It was nicknamed "Friar Tuck" because their leader Roland Tembo was unable to pronounce its genus name. This individual was later freed by Gatherers Dr. Sarah Harding and Nick Van Owen, though it is unknown if it survived.

Jurassic World

A new set of clones was created by InGen for Masrani Global Corporation's Jurassic World. These new clones were close to the size of the originals. The new clones' skin was dark red with lime spots and a lime underbelly. They resided in the self-titled Pachy Arena where visitors could watch them have on of their famous head-butt duels. Every time they butt heads, their implants became temporarily disabled, which allowed the Pachycephalosaurus to escape the Pachy Arena without being tracked.

Before the 2015 Isla Nublar Incident, a Pachycephalosaurus broke out of the Pachy Arena but was tranquilized and returned to the paddock by some Asset Containment Unit workers.

Jurassic World Fallen Kingdom

They were not seen in Jurassic World: Fallen Kingdom might have fallen back to extinction. According to the Dinosaur Protection Group website it shows a pair of Pachycephalosaurus in the forest. It's unknown if they were in the stampede during Mount Sibo eruption. They might have been rescued and sold by the buyers or escaped the estate offscreen since the sounds of Pachycephalosaurus were heard in their cages as they panicked from the poisoning gas.


Known Pachycephalosaurus


Strength and Combat

Lost world pachy headbutt small

Pachy headbutting jeep

A Pachycephalosaurus from Jurassic World headbutt each other because as Robert Burke explains, the Jurassic World Pachy spine can line up with its' head lower down to absorb impact. They can make a dent into a jeep and knock a person from the same side of the jeep out the other end.

Acrobatic and Speed

Durability and Stamina

Possible young Pachy have shown to fully charge to hit a jeep was able to show not to munch sign of struggle to get hurt.