More than 100 years ago, paleontologist E. D. Cope of “Dinosaur Wars” fame found a few fragmentary bones of a reptile in the deserts of New Mexico. He named the reptile Typothorax. A century later, Typothorax — which belongs to a group of reptiles called aetosaurs — remained something of a mystery, known mainly from pieces of armor, a few limb bones, and some sections of tail. Now, thanks to two remarkably complete skeletons, paleontologists are finally revealing what Typothorax really looked like.