Parasaurolophus is a hadrosaurid species of dinosaurs, from the Upper Cretaceous (about 76-65 million years ago) of North America. It was about 10 m (33 ft) long, 5.2 m (17 ft) high and weighed approximately 3500 kg (7,700 lb). Parasaurolophus was two-legged (bipedal), though most likely stood on four when resting. It also had two strong arms, a scaly skin and a powerful tail. Its most noticeable characteristic is a long curved crest protruding from its head, often longer in males than in females. It was probably used for intraspecific communiqué by both males and females and for display by the males. There were about three species, but two of them are known only by unfinished remains. The best known species is Parasaurolophus walkeri, the one that appears in the Jurassic Park movie.

There has been a lot of controversy over the bent crest of this dinosaur. Some scientist used to think that the crest had a skin "flag" that connected the neck. There is no evidence to this.

Parasaurolophus lived in big herds. They lived on grassy plains but liked to be around water. They were herbivores but they were not, as some people consider, aquatic or water plant-eaters; actually, they were fully terrestrial animals. They could almost certainly swim, but they lived their entire life in land. Parasaurolophus were quarry for large, carnivorous theropods such as Tyrannosaurus rex.

Fossils of Parasaurolophus have been established across North America, as well as in Canada, where a complete skeleton was established.

 

Parasaurolophus appeared in the Jurassic Park films, in the Brachiosaurus scene, when the camera trails to a full sight of the park, in a herd near the lake. Parasaurolophus appeared again in The Lost World: Jurassic Park when InGen tries to capture dinosaurs for the San Diego Jurassic Park. They also made a brief look in Jurassic Park III, as a stampeding herd frightened by the look of a group of humans trying to escape from a pack of angry raptors.