Discover a dinosaur that even T-rex may have steered away from: the heavily armored Sauropelta. Sauropelta was a medium-sized armored dinosaur that lived in North America during the Early Cretaceous, about 108 million years ago. This peaceful plant eater used its protective array of bony armor and spines to defend itself from hungry hunters. It reached about 17 feet long. It had a small beaked head, a long tail, and walked on all fours. It had five fingers and four toes. Most notably it had an impressive covering of armor that consisted of bony plates on the back, hips, and tail, a row of triangular spine-like projections along its flanks, and large pointed spines on its neck.