Parasaurolophus was a Late Cretaceous hadrosaur from North America known for the long, hollow crest extending back from its skull. Because that crest contained looping air passages, scientists have used fossil scans and computer models to reconstruct the low sounds it could have produced, making it one of the few dinosaurs with a scientifically modeled voice. That reconstruction helped the call spread through documentaries, games and online edits, where creators use it as a more believable alternative to generic movie roars.