Ankylosaurus, ang kuh luh SAWR uhs, was a large, armored dinosaur that lived between 68 million years and 65 million years ago in what is now western North America. The name Ankylosaurus means fused lizard and describes the dinosaur's armor, which consisted of bony pieces that had fused, or grown together. This heavy armor protected all the exposed parts of the body, including the head, back, and tail.