The Rise and Fall of the Dinosaurs: A New History of a Lost World: The Definitive Dinosaur Encyclopedia with Stunning Illustrations, Embark on a Prehistoric Quest!

by Steve Brusatte

You could call T. rex the James Dean of dinosaurs: it lived fast and died young. And all of that hard living put a tremendous strain on its body. The skeleton had to endure the daily addition of five pounds during the spurt years. Somehow the body had to morph from wee hatchling to monster, so it comes as no surprise that the skeleton of T. rex changed dramatically as it matured. As youngsters, they were sleek cheetahs, as teenagers gangly looking sprinters, and as adults pure-blooded terrors longer and heavier than a bus. The younger ones probably ran a lot faster than the adults and maybe could have chased down their prey, whereas the silverbacks were so huge that they could only ambush and relied much more on their strength than their speed. What’s particularly frightening is that juveniles and adults seemed to live together in packs, meaning they may have hunted in teams, complementing each other’s skills to make life hell on their prey.