Pachycephalosaurus

Pachycephalosaurus spinifer
Name meaning	Thick-Headed Lizard
Biology
Height	N/A
Length	4-5 meters
Weight	450 kilograms
Wingspan	N/A

Pachycephalosaurus is a genus of pachycephalosaurid dinosaurs. The type species, P. wyomingensis, is the only known species. It will be one of the playable dinosaurs in the base game of Saurian.

Information

Pachycephalosaurus lived during the Late Cretaceous Period (Maastrichtian stage) of what is now North America. Remains have been excavated in Montana, South Dakota, and Wyoming. It was an herbivorous creature which is primarily known from a single skull and a few extremely thick skull roofs, though more complete fossils have been found in recent years. Pachycephalosaurus was one of the last non-avian dinosaurs before the Cretaceous–Paleogene extinction event.

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, and fruits. The sharp, serrated teeth would have been very effective for shredding plants.

Paleontologists have heavily debated for several decades the adaptive significance of pachycephalosaurid domes. A study from Horner suggested that the skull roof could probably not have adequately sustained impact associated with such ramming and would have been risky. However, more recent studies showed that pachys did headbutt, due to the discovery of lesions in the skull which could only be caused by head trauma. And although pachycephalosaurs with flatter, smaller domes — which paleontologists believe were females and juveniles — were included in the study sample, none of them appeared to have suffered any trauma. This suggests not only that head-butting was limited to adult males but also that — if modern animal behavior is any indication — it was likely used by them to fight over females which is most likely. Some scientists had previously theorized that the dinosaurs’ peculiar domes were sex characteristics intended to attract mates, like an elk’s antlers or a peacock’s tail feathers. The new study intimates that the bony crests were meant not only to draw the eye but also to fight for the right to mate. This is not unlikley as it would serve as a very prominent piece on it's head.

While Pachycephalosaurus is only known from a 25 cm (10 in) skull, based on other pachycephalosaurids, it has been estimated that Pachycephalosaurus was around 4.5 meters (15 ft) long and weighed 450 kilograms (990 lb). Based on other pachycephalosaurids, it probably had a fairly short, thick neck, short fore limbs, a bulky body, long hind legs and a heavy tail, which was likely held rigid by ossified tendons.

Physical appearance

As an adult, Pachycephalosaurus is fully scaled with a spiny tail and skin on the legs called uropatagium. Its' color is gray with brown stripes to match its' habitat and a red face and throat for display and white dome. Males of this species have bright red heads.

Behavior and Biology

Pachycephalosaurus is a vulnerable prey animal in the Hell Creek, preferring to live in densely forested areas to avoid predators such as Tyrannosaurus, yet is hardy and belligerent and will attack Dakotaraptor or young Tyrannosaurus when provoked. Pachycephalosaurus uses its bone-breaking domed head as a multifunctional tool, being used to defend against as previously mentioned, territorial disputes, and to deflect forest foliage while running. These dome-headed dinosaurs mate for life and both parents raise their young for several months. Males are fiercely territorial and will engage in head and flank butting contests. Pachycephalosaurus are herbivorous animals, feeding on low-growing vegetation as well as fungi and occasionally insects.

Gallery

Pachycephalosaurus attacking animations

For a more complete gallery, visit Pachycephalosaurus/Gallery

Behind the scenes

Pachycephalosaurus has gone through several design changes over the course of the game.

Chris Masna created early concepts on the Pachycephalosaurus depicting them with vibrant colors as opposed to later designs of Pachycephalosaurus. RJ Palmer created further designs of the Pachycephalosaurus. The first by Palmer was released on November 18, 2014, and featured prominent spikes on the skull, a sail running down most of the back, and spikes at the tip of the tail. Palmer then created another design that lacked the traits of his previous concept and had a larger tail. This design was later chosen for the in-game model until it was scrapped on September 15, 2016.

The former genera Stygimoloch and Dracorex  are the subadult and juvenile of the Pachycephalosaurus, which is what is believed to be accurate. It is still debated, however, as they may be different genera.