How fast did T. rex and other predatory dinos run?
Earlier generations of museumgoers gazed on slouching, tail-dragging dinosaurs. But when the notion of warm-blooded dinosaurs took hold, goliaths like Triceratops and Tyrannosaurus rex got a spring in their step. Since Triceratops had legs proportioned like those of a rhinoceros, some researchers concluded that they charged at a full gallop. And predatory dinosaurs became the leopards of the Mesozoic Era, with T. rex hitting 40 miles an hour. It was a startling vision, and it made Jurassic Park a hit. Giganotosaurus goes on the prowl. The theropod thrived 100 million years ago, some 25 million years before T. rex. Roughly six feet bigger than T. rex and a ton or two heavier, Giganotosaurus nonetheless was a relatively fast dinosaur whose pointed tail apparently provided balance and the ability to make quick turns as it ran. Fossil evidence suggests its prey included Argentinosaurus, a 125-foot-long herbivore. Now scientists are finally putting this image of dinosaurs to a real biomecha
