3. Gang Killers

In south central Montana, a group of bird-like predators called Deinonychus are unearthed, altering our view of dinosaurs forever. Scientists are quick to recognize that these creatures, equipped with a deeply recurved sickle-shaped claw, do not fit into the image of a slow-moving, cold-blooded dinosaur. Lying next to the skeletons of these raptors were the remains of a large plant-eating dinosaur called Tenontosaurus. Modern CAT Scanners help scientists get a never-before-seen look into how these animals moved, fought and behaved. Watch as experts recreate what happened when a pack of deadly raptors took on an adversary more than twice their own size.