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.