|Time:||Cretaceous period, between 73 and 69 million years ago|
|Range:||North America; Alaska, USA and Alberta, Canada|
|Maximum Speed:||15 mph|
The skull of Pachyrhinosaurus was massive; only Triceratops, Pentaceratops, and Torosaurus had larger skulls. Pachyrhinosaurus may have used the bony growth, or boss, on its nose to butt other herd members for dominance and mating – like a rhino. The function of the neck frill and horns is unknown.
Pachyrhinosaurus used its strong teeth cheek to chomp on tough fibrous plants and its sharp beak to slice vegetation. Packed tightly together to form a cutting surface, its teeth were continually replaced by new ones- just like a shark’s teeth. This adaptation made it a more efficient feeder.
Pachyrhinosaurus probably hatched from eggs. Parents probably cared for the young. When threatened by predators, they may charge into its enemy like a modern-day rhinoceros does.
At the Zoo: Indian Rhinoceros
Although it has been widely believed that rhinos are dangerous and formidable fighters, they usually flee from danger. Instead of using their horns as weapons, they prefer to use their lower incisors. Male Indian rhinos do fight each other during mating season, although they tend to tolerate other males in their territories in other seasons.