Pachycephalosaurus Fact Sheet

Source: Fred Wierum, CC BY 4.0, via Wikimedia Commons

Ready to learn about the thick-skulled dinosaur called the Pachycephalosaurus? This dinosaur fact sheet about the Pachycephalosaurus is free to download as a printable PDF document.

What does the name Pachycephalosaurus mean?

Pachycephalosaurus translates to “thick-headed lizard”. It was given that name because of its extremely thick skull dome.

What family was the Pachycephalosaurus from?

The Pachycephalosaurus is part of the Pachycephalosauria family. It is a family of dinosaurs that were herbivores/omnivores and walked on two legs. Scientists say most types of Pachycephalosaurus were herbivores. But there is evidence that some types had a blended diet and ate meat and plants.

What did the Pachycephalosaurus eat?

The Pachycephalosaurus was a herbivore, existing on prehistoric plant life. It is uncertain what the Pachycephalosaurus ate, but it is assumed that it ate a diet of leaves, seeds, and fruit. It has also been suggested that meat may have been included in the diet due to its front teeth similar to other carnivore therapods.

When and where did the Pachycephalosaurus live?

The Pachycephalosaurus lived in what is now North America during the end of the Late Cretaceous Period, about 70 million to 66 million years ago. Remains have been found in Montana, South Dakota, Wyoming, and Alberta.

How big was the Pachycephalosaurus?

It is believed that the Pachycephalosaurus could grow to 4.5 m (14.8 ft) long, 6 ft tall, and weigh about 450 kilograms (990 lb).

When were the first remains of a Pachycephalosaurus found?

The first remains of the Pachycephalosaurus were found as early as the 1850s. As determined by paleontologist, Donald Baird, in 1859 or 1860, a bone from the back of the skull was found by fossil collector Ferdinand Vandeveer Hayden at the Lance Formation in southeastern Montana.

What are some unique features of the Pachycephalosaurus?

The most distinctive feature of the Pachycephalosaurus is the large, thick bony dome of the top of its skull. The bone is about 25 cm (10 in.) thick with bony knobs and blunt bony spikes at the rear of the dome that projected upwards from the snout.

The function of the dome is uncertain, but it has been proposed that it was used to help defend against predators, to attract mates, or to head-butt other Pachycephalosaurus as a way to ward off rival males during mating. However, the last suggestion is not wildly believed to be the case because of the lack of healed scars on the skull.

What are other interesting facts about the Pachycephalosaurus?

Palontolgoist first mistook the skull of the Pachycephalosaurus to be a dinosaur’s kneecap.

The Pachycephalosaurus only has one type of valid species called P. wyomingensis, named by American Paleotolgoist Charles W. Gilmore in 1931.

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