Tyrannosaurus rex was a dinosaur that lived up to its name. If you were to visit its haunts between 68 and 66 million years ago, you wouldn’t find another carnivore quite like it. Growing up to 40 feet long and weighing as much as nine tons, the dinosaur was far larger than any other meat-eater of the time. And that’s strange. In other times and places, habitats were full of carnivorous dinosaurs of all sizes.