Living during the Late Cretaceous Period, Hypacrosaurus was a typical hadrosaur. A hadrosaur was a dinosaur with a duckbill, which is why they are commonly called duck-billed dinosaurs.
The front of Hypacrosaurus' mouth began with a toothless bill, followed by rows of self-sharpening teeth located further back in the mouth near the animal's cheeks. How did these teeth self-sharpen? The top teeth were set in the animal's mouth at an angle to the bottom teeth that caused them to grind against each other.
The tail of Hypacrosaurus was very long and stiff. It would have been used as a weight to balance the animal as it darted quickly from side to side evading predators.
Like many other duckbills, Hypacrosaurus had a hollow crest located on the top of its head. It is believed that these crests were used to make loud horn blasts that could have been heard from a reasonable distance.
Hypacrosaurus had large eyes compared to other dinosaurs. These keen eyes were probably used to detect enemies like Tyrannosaurus.