The mysterious song of the dinosaurs

Dinosaurs almost certainly didn’t roar. Researchers have yet to find any fossilised evidence of sound-producing organs like those of modern birds or mammals, so Tyrannosaurus rex probably resorted to closed-mouth vocalisation — low-frequency sounds that are made by inflating the throat. Computer simulations of a hadrosaur’s hollow head-crest showed that it could double as a resonating chamber.