The Largest Predatory Dinosaur from the late Cretaceous period. It is the most popular of all the dinosaurs. It lived in Western North America during the time. It lived a life either as a scavenger or a top predator. It is believed that they live in packs or killing gangs. They where good parents, taking care of there young up to the average age of a teenager. A Tyrannosaurus life span is similar to a Human. Most Tyrannosaurus barely lived past the age of 30 years. The small arms of the Tyrannosaurs was not meant for anything except one thing. Reproduction; lately scientists has examined the arms and found that the arms where strong but meant to hold the opposite sex while reproduction. But it most likely helped it get up after falling or taking a nap. The arms can lift 400 pounds each. They are also known to hunt large sauropods, Ceratopsians, Hadrosaurs, Pachycephalosaurs, and Ankylosaurs.