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Parasaurolophus

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Parasaurolophus
Temporal range: Late Cretaceous
Parasaurolophus walkeri
Scientific classification
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Parasaurolophus

Parks, 1922
Species
  • P. walkeri (type)
  • P. tubicen Wiman, 1931
  • P. cyrtocristatus Ostrom, 1961

Parasaurolophus was a genus of hadrosaurid (duck-billed) dinosaur from (in theroy) the Upper Cretaceous Period (about 76-65 million years ago) of what is now North America. Its name means 'near crested lizard', which refers to another hadrosaurid, Saurolophus, discovered before Parasaurolophus. Three species are currently recognised.

Description

Parasaurolophus were about 10 m (33 ft) long, 5 m (16 ft) high and weighed around 3500 kg (7,700 lb). Like other hadrosaurs, they were facultatively bipedal, i.e. they could alternate between two legs and four, probably preferring a quadrupedal gait while they foraged for food and assuming a bipedal mode for faster running.

Parasaurolophus walkeri skull - Natural History Museum, London.

Their most noticeable feature would have been the six-foot long curved crest, protruding from the rear of the head, often longer in males than in females. This hollow crest was probably used for intraspecific communication by both males and females and for display by the males. In the vertebrae there was a cut where the horn would hit the back, this prevented the horn from hitting the back. Many scientists also think the crest gave Parasaurolophus an excellent sense of smell. Other notable speculation is that the crest may be a defense mechanism of some sort, such as the modern day Bombardier Beatle's ability to throw a jet of chemical "fire" at their enemies.[verification needed] Parasaurolophus is often depicted with a flap of skin running from the bottom of the crest to the base of the neck, though there is no evidence of this. There were about three species but two of them are known only by incomplete remains. The best known species is Parasaurolophus walkeri.

Discovery and species

Fossils of Parasaurolophus have been found across North America, including much of a skeleton in Alberta, Canada, and partial skulls in New Mexico, USA.

Paleobiology

Parasaurolophus probably lived in large herds and inhabited flood plains. They were herbivores but they were not, as was once thought, aquatic. They were fully terrestrial animals, as evidenced by footprints. They could possibly swim but they lived their entire lives on land. Parasaurolophus may have been prey for large carnivorous theropods, such as Daspletosaurus.

Parasaurolophus cyrtocristatus.