Euoplocephalus, meaning “well-armored head”, is a genus of ankylosaurian dinosaur from the Late Cretaceous Period (Campanian-Maastrichtian age) of about 85 to 65 million years ago. It was discovered in 1902 by paleontologist Lawrence Morris Lambe. It was originally called Stereocephalis, but since that name was already taken by an insect, it was changed to its current name in 1910, by Lambe. Fossils from more than 40 individuals have been recovered from bone beds in Alberta, Canada and Montana, USA. It is the best known ankylosaurid dinosaur.
Euoplocephalus was one of the largest ankylosaurian dinosaurs that existed. It was about 20 feet long and weighed nearly 2.2 tons. It had short, stout legs. The rear legs were larger than the front legs and all four feet had hoof-like claws. The skull was flat, thick and triangular. The beak was horned and the teeth were small, almost leaf-shaped. The neck was short. The head and body was covered in bands of armor. Despite the amount of armor, it was a rather flexible animal. Its eyelids were also armored to protect it when its eyes were closed. Its tail was club-like.
The armor of this animal has been well documented. Each piece of armor was composed of a thick oval plate, embedded in thick skin, which was studded by short spikes, similar to those of crocodiles. Each spike was 3.9 to 5.9 inches long. It had spines running all the way down the back, and horns protruding form the back of the head. The bony club-like tail was very muscular, and it could have easily swung its tail from side to side for defense. Many of its internal bones were fused together to help support the massive armor. The only part of the body that wasn”˜t well armored was its belly. This would have been a tough animal to prey upon.
Euoplocephalus was a plant eating dinosaur. Its nasal structure was complex, which indicates that it may have had a good sense of smell. The flexible legs may have been good tools for digging. Its teeth were poorly constructed and leads one to believe it ate mostly low-lying vegetation and shallow tubers. It is unknown if this dinosaur lived a solitary life or if it lived within a herd. Conventional wisdom places ankylosaurian specimens as solitary beasts, but a recent discovery of 22 young Pinacosaurus fossils, indicate that some ankylosaurian dinosaurs may have lived in groups.