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