Pachycephalosaurus

## *Pachycephalosaurus wyomingensis*

***Pachycephalosaurus*** (name meaning "*Thick-Headed Lizard*"), often nicknamed ***Pachy*** for short, is a genus of pachycephalosaurid dinosaur that originated during the Late Cretaceous period of what is now North America. Measuring 5 meters long and weighing 1 ton, *Pachycephalosaurus* is one of the world's most recognizable dinosaurs, identifiable by its thick, domed skull.

In the Series 1 finale "*End of the Road,*" a small herd of *Pachycephalosaurus*, consisting of five adults and eight juveniles were went extint from Late Cretaceous Montana, 65 million years ago.

## Facts

### Era & Discovery

*Pachycephalosaurus* lived in western North America during the Late Cretaceous period, from 77 – 65 million years ago. Therefore, it died out with the other dinosaurs at the end of the Cretaceous. It shared its environment with other dinosaurs like the hadrosaurs, ceratopsians, and ankylosaurus as well as the Raptors and tyrannosaurs that saw it as prey.

*Pachycephalosaurus* remains were first discovered in the early 1850s but the dinosaur itself was not named until 1931 by Charles W. Gilmore. Remains have been excavated in Montana, South Dakota, and Wyoming. *Pachycephalosaurus* has also become one of the most well-known dinosaurs in the world.

### Physical Attributes

*Pachycephalosaurus* is the largest known pachycephalosaur, growing to be about 6 – 7 feet (2 – 2.2 m) tall, measured 15 – 17 feet (4.6 – 5.2 m) long, and weighed around 1 ton (2,000 lbs.) It also possessed long legs and small forearms. Its head was equipped with a small beak, round eyes, and most notably an extremely thick, domed skull roof.

The thick, well over 9-inch skull domes of *Pachycephalosaurus* was used in infraspecific combat, for example, bashing heads during the mating season, just like the modern ibex do. It is also likely that the animals butted their heads against each other's flanks during the mating season, not unlike giraffes do today. Given the chance, it is also possible they used their heads to defend themselves against predators. Additionally, the head of *Pachycephalosaurus* is strong enough to burst through a concrete wall.

### Behavior & Traits

*Pachycephalosaurus* lived in small herds of around, at maximum, six other individuals in a single herd. Like many herbivores, *Pachycephalosaurus* often separated while feeding, which often gave many predators an advantage to attack.

*Pachycephalosaurus* was generally a highly curious creature, known to follow interesting other animals like humans around and to investigate other things of interest. However, when dealing with its own kind, *Pachycephalosaurus* could be highly aggressive, attacking other *Pachycephalosaurus* (or at least what it thought to be them) with a powerful headbutt. *Pachycephalosaurus* also didn't seem to be highly intelligent, as it could mistake its own reflection for another *Pachycephalosaurus*.

Much like the larger ceratopsians, *Pachycephalosaurus* jousted with each other. The young did it for fun, but the adults fought for dominance. With their heads measuring more than 9 inches thick (therefore, making them in comparison to a battering ram) and their spines built to withstand the impact of the hit, it would be very painful to get hit by a *Pachycephalosaurus*.

## Gallery

Pachycephalosaurus.jpgPachycephalosaurus3.jpgDino10.jpg
## Trivia

* *Pachycephalosaurus* is the largest pachycephalosaur to be introduced to the museum.
* The sound effects of *Pachycephalosaurus* are that of bull and horse sound effects.