Dino Index

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Latin Name Pachycephalosaurus
Everyday Name Pachycephalosaurus
Length 6 meters
Height 8 meters
Weight 1,800 kg
Diet herbivore
Period Cretaceous
Pronunciation Pah - key - seh - faah - low - soar - us

A True Bone Head

Pachycephalosaurus is a very distinct dinosaur. It has a domed head unlike almost any other dinosaur. The dome is even more peculiar in that it is solid bone almost 23 cm thick. That plus bony protrusions around the edges of the skull would have made this a very interesting site.

Two Legs?

This dinosaur walked on two legs. As I researched this dinosaur, I found it interesting that many sources say it is bipedal, but no bones except for the skull have been found. We can sometimes infer things about bones we did not find from the bones we did but this inference seems a bit far for me.

Easy Diet

The diet on the other hand, is a bit easier to determine since we have teeth. The teeth are mostly small and not very strong looking. From this we can see that they could not have chewed tough fibrous plants. The teeth were also sharp so it seems reasonable to say that they probably ate leaves and fruit, with insects mixed in.

A Hunter?

The interesting thing to note is that the eyes were quite forward facing. This would give pachycephalosaurus binocular vision. Binocular vision is common among carnivores as it helps them for hunting. So this dinosaur may have been omnivorous.


The most intriguing thing about this dinosaur of course is the thick bony skull. At first, scientists assumed it was used for head-butting, rather like bighorn sheep today. However, several facts seem to point away from this as a reason for the skull to be so thick.

Fact One

First, if this species did head butt, there would be certain characteristic scars on the top of the skull. The bones that we have found so far don’t have those scars.

Fact Two

Next, the skull bone would have to be quite strong so it would not break with this crashing heads activity. The problem is that the bone may not be that strong even though it is thick.

Fact Three

Another problem is the neck.We do not have the neck bones, but the angle that the neck bones attach to the skull is a common one for a U-shaped neck. This U-shape would be bad for transmitting the energy from a direct collision like a head butt.

So this hard head was more likely used to butt into the flanks of other dinosaurs like itself, by swinging its head into their sides. In fact, it seems that they had a very wide body, which might have given the protection to the internal organs for such fighting, so this explanation seems good.