Euoplocephalus was one of the most common dinosaurs to live in North America around 70 million years ago. Because they were so plentiful, their fossils have been found in a number of locations.
These fossils show that Euoplocephalus was well protected. Even its eyelids had bony protrusions protecting the eyes.
Euoplocephalus had spikes or horns on the side of its head and also running down its armored back. Its stiff tail ended with a hammer which it would have used to try and break the legs of enemies, such as Tyrannosaurus.
Euoplocephalus was discovered and named in 1910 by Lawrence Lambe.