Parasaurolophus

Parasaurolophus is a genus of herbivorous hadrosaurid dinosaur that lived during the Late Cretaceous Period, around 76.5 to 74 million years ago. It is known for its distinctive crest on the back of its head, which was likely used for visual display and/or as a resonating chamber to amplify the animal's calls. Parasaurolophus was a medium-sized dinosaur, measuring around 9 meters (30 feet) in length and weighing around 2.5 metric tons (2.75 short tons). It had a long, low profile and walked on all fours. It had a long, slender snout and a jaw that was lined with hundreds of small, interlocking teeth, which it used to grind up plant material. It probably lived in herds and fed on a variety of low-lying plants, including ferns and cycads.