Did dinosaurs communicate?

Dinosaurs possibly communicated both vocally and visually. The chambered headcrests on a few dinosaurs such as Corythosaurus and Parasaurolophus might haved been used to amplify grunts or bellows. Defensive posturing, courtship activities, and territory fights possibly involved both vocal and visual displays. An annoyed Triceratops bull shaking his head at you, even noiselessly, would have made himself very clearly understood!