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Pachyrhinosaurus

'Thick-nosed lizard'

WWD - Prehistoric Planet

Pachyrhinosaurus was a rhinoceros-like dinosaur with horns, frill, bony ornaments and a beak.

They call it home

Pachyrhinosaurus lived in Cretaceous Alaska and Alberta. With some of its range near the poles, these dinosaurs would have experienced long winters and months of darkness.

What we heard about their hearing

What we heard about their hearing

With relatively small and primitive hearing apparatus, it is likely that Pachyrhinosaurus would not have had very good hearing.


What big teeth you have

What big teeth you have

As a herbivore, Pachyrhinosaurus had strong, stubby, cheek teeth. These were packed tightly together to form a single continuous cutting surface for slicing food into small pieces, like a pair of prehistoric scissors.

Nose knowledge

Nose knowledge

Like its hearing apparatus, the olfactory centres of Pachyrhinosaurus were reduced, which means its sense of smell was poor.

The most fantastic find

The most fantastic find

In 1973 at Pipestone Creek, Alberta, Canada, science teacher Al Lakusta discovered hundreds of Pachyrhinosaurus remains. This bone bed suggests that, about 73 million years ago, a herd of juvenile and adult individuals died in a flood. The remains have given us a unique insight into the lifestyle of these animals.

Pachyrhinosaurus features

Pachyrhinosaurus features Height: 2.5m (8.2ft)
Length: 7m (22.96ft)
Weight: 3 tonnes (3.36 short tons)
Top speed: 45kph (28mph)
Vision: Pachyrhinosaurus had poor vision. Palaeontologists have studied its brain cavity and found that the optic centre which controls the animal's vision was not well developed.
Skin: Pachyrhinosaurus' skull bore massive reinforced bones – called bosses – over its noses and eyes, most probably for display and head butting rival males. The animal's horns and other bony ornaments were smaller than its bosses and the arrangements differed depending on the species of Pachyrhinosaurus. The frill was also topped with a prominent pair of horns.
Brain: Pachyrhinosaurus had a small, poorly developed brain. It was not a bright animal.
Prey: Herds of Pachyrhinosaurus needed vast areas of vegetation in order to sustain their numbers. To get them through the polar months, some scientists believe they might have migrated hundreds of miles to warmer climates.
Bite: Pachyrhinosaurus used its battery of strong cheek teeth to chomp on low-lying tough fibrous plants and its sharp beak to slice vegetation.
Nest: Scientists have uncovered a nest from a Protoceratops, a relative of Pachyrhinosaurus. The nest was round in shape, measuring 0.7m (2.3ft) in diameter and containing 15 baby dinosaurs. Pachyrhinosaurus would probably have had similar nests.

Pachyrhinosaurus facts and theories

Pachyrhinosaurus facts and theories

  1. Pachyrhinosaurus had tooth batteries so that worn teeth could be replaced by new ones, like a conveyor belt system. This increased the efficiency by which they chomped on their tough plant material.
  2. New discoveries of Pachyrhinosaurus are being made all of the time. One new species was described in 2011. It was named after Ross Perot, a famous businessman who has funded a number of scientific expeditions and ran for the US presidency twice.
  3. Pachyrhinosaurus and other horned dinosaurs are thought to have fed on newly evolved flowering plants.
  4. Pachyrhinosaurus fossils are often found with, or near, fossils of the duck-billed dinosaur Edmontosaurus. Both species lived throughout Alberta and into Alaska. It is likely that they shared a similar environmental preference and might have even travelled in herds together.
  5. Fossils have been uncovered in which both adults and juveniles are found together, suggesting that Pachyrhinosaurus might have protected its young within a large group, like many herding animals do today.