One of the most famous and fearsome dinosaurs, T. rex lived during the Late Cretaceous (around 68–66 million years ago). As an apex predator, it measured up to 40 feet (12 meters) in length, stood about 13–15 feet (4–5 meters) tall at the hips, and weighed between 9–14 tons. It had powerful jaws lined with teeth capable of crushing bone, a robust skull, and tiny but functional arms. Its diet included large prey like hadrosaurs and ceratopsians.