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 the exposed parts of the body, including the head, back, and tail.
Ankylosaurus was one of the largest of the armored dinosaurs. It was about 25 feet (7.6 meters) long and weighed about 4 to 5 short tons (3.6 to 4.5 metric tons). It was a plant-eater with small teeth. The dinosaur’s triangular skull was 21/2 feet (76 centimeters) long and equally wide. A spike stuck out from each cheek, and two more stuck out from the back of the head. Short, thick legs supported the weight of the dinosaur’s low, broad body. The tail ended in a big, heavy ball of bone.
When attacked, Ankylosaurus may have crouched down and pressed itself to the ground. In this position, the attacker could only bite or claw at the thick, hard armor. Ankylosaurus also may have defended itself by swinging its tail and hitting an attacker with the bony club at the end.
