Sixty-six million years ago, two genera of long-necked, quadrupedal dinosaurs had an advantage over other sauropods: they could easily stand on their hind legs for extended periods. This allowed them ...

Dinosaur skeletons often dominate museum halls, from the towering Tyrannosaurus rex known as Sue in Chicago to Sophie the Stegosaurus in London. These fossils shape how you picture dinosaurs. Yet ...