Parasaurolophus walkeri

Parasaurolophus is a distinctive and well-known dinosaur from the Late Cretaceous period, approximately 76 to 74 million years ago. It was a herbivorous hadrosaur, or "duck-billed" dinosaur, recognized for its long, backward-curving crest that extended from the top of its head, which was likely used for communication, display, or possibly even temperature regulation.

Parasaurolophus had a body length of about 30 feet (9 meters) and weighed around 2.5 tons, with a long, low-slung body supported by sturdy, pillar-like legs. It had a broad, duck-bill shaped mouth that was capable of processing large amounts of vegetation, such as cycads and conifers, which made up its diet.

The most distinctive feature of Parasaurolophus was its crest, which varied in size and shape among different species. The crest was hollow and connected to the nasal passages, and it's believed that the dinosaur may have used it to produce distinctive vocalizations, possibly for mating calls or to communicate with others of its kind. The crest’s size and shape may also have been a visual signal for dominance or mate attraction.

Fossils of Parasaurolophus have been found in North America, particularly in the western United States and Canada. This dinosaur is often depicted in popular media due to its striking appearance and the mystery surrounding the exact function of its crest. Despite the various theories, much of the purpose of the Parasaurolophus crest remains speculative, making it one of the most intriguing and iconic dinosaurs of its time.