T-rex Coloring Pages: Tyrannosaurus Rex, was a massive creature that lived millions of years ago during the late Cretaceous period. It was one of the largest carnivorous dinosaurs, measuring up to 40 feet in length and weighing up to 9 tons. The most striking feature of the T-Rex was its large head with powerful jaws filled with sharp teeth that could crush bones with ease. Its short arms were strong and ended in two-fingered hands, while its powerful legs ended in large feet with sharp claws. The T-Rex had a long tail that helped it to balance while running and hunting for prey. Overall, the T-Rex was a fearsome predator with a distinctive appearance that made it one of the most well-known dinosaurs in history.