Euoplocephalus body was covered in "armour", which was actually bone plating, which protected it from predators. Its tail was a giant club, much like a mace, that could be used as a weapon to defend itself from predators. It is believed that it would lay down and pull its limbs under the boney plates to keep itself from being damaged, and then it would swing its tail until a predator lost interest or became mortally injured by the club like tail. Some paleontologists believed this was such a good adaptation that if the great extinction didn't occur Euoplocephalus might still have been alive today.
The genus name Euoplocephalus, meaning "well-armed head", is derived from the Greek words eu (εὖ) meaning "well", hoplo~ (ὁπλο~) meaning "armed", and kephale (κεφαλή) meaning "head". This name has been misspelled more than a dozen different ways in formal scientific literature. The specific name tutus means "safely protected" in Latin. The only valid species known today is Euoplocephalus tutus.
In the Media
Euoplocephalus was a dinosaur featured in the novel, Jurassic Park. Its relative, Ankylosaurus, was featured in the third Jurassic Park film, as well as the game Jurassic Park: Operation Genesis. It has also appeared on the updated version of Walking with Dinosaurs website.