Parasaurolophus

One of the more unusual dinosaurs is the tube-crested hadrosaur Parasaurolophus.   This large herbivore from the Late Cretaceous period has been beloved in our family since my oldest son decided this was his favorite dinosaur quite a few years ago.  While fossils of Parasaurolophus are quite rare, there are a few really good Parasaurolophus exhibits.

Fossil Focus: Parasaurolophus

A member of the hadrosaur family, which is known for their flat, duckbill-like faces, Parasaurolophus was a dinosaur that that could walk on either two or four legs. When you first see a Parasaurolophus, the most obvious feature is the huge crest on its head.  The long, curved cranial crest, which extended two or three feet behind the skull, is quite remarkable and fairly unique among dinosaurs.  The crest has been the subject of much debate in paleontology circles since its discovery in 1920 in Alberta, Canada.

Early depictions of Parasaurolophus showed the dinosaur spending most of its time in the water, as many dinosaurs were depicted.  This theory was popular for several decades starting in the 1920’s or so.  In fact, one early guess at the function of the crest on Parasaurolophus was that it worked like a snorkel, allowing the animal to forage or hide from predators underwater for a long period of time.  This theory and others suggesting an aquatic lifestyle were later debunked (for example, there is no hole at the end of the crest to allow a snorkel-like function), and now it is known that hadrosaurs were certainly terrestrial animals.

The crest of the Parasaurolophus itself is interesting–not only is the shape unique among dinosaurs, but it contained hollow tubes that connected with the nasal cavity.  This means that a Parasaurolophus could blow through its nose and use the resonating chamber in the crest to make loud honking sounds, with a design much like that of a trombone. Studies of the crest support this hypothesis, and it is now theorized that the primary function of the crest was communication, although it likely also played a role in sexual display and mate selection, as well as species recognition.

A wonderful display demonstrating the sound-making capabilities of the Parasaurolophus can be found in the “Evolving Planet” exhibit at The Field Museum in Chicago.  Right next to the skeletal mount of the dinosaur is a display which allows visitors to push an accordian-like device to create a sound that mimics what a Parasaurolophus might have sounded like.   This is a very popular exhibit with children and adults alike and helps make this dinosaur a favorite for many.

There are three species of Parasaurolophus that are recognized, two with very similar crests (P. walkeri and P. tubicen) and a third (P. cyrtocristatus) with a smaller, more rounded crest.  Some paleontologists believe that the P. cyrtocristatus may be a female specimen showing sexual dimorphism, although others disagree.  While the genus was first discovered in Canada, Parasaurolophus finds have been extremely rare in the north.  Most of the Parasaurolophus specimens have been found in New Mexico and Utah.  The most complete specimen was found by a California high school student in Utah in 2009 who discovered the mostly complete remains of a juvenile, estimated to have died at an age of about one year.  That specimen is on display at the Raymond M. Alf Museum in Claremont, California.

While perhaps not as popular as fellow herbivores like Triceratops and Stegosaurus, the Parasaurolophus is certainly an iconic dinosaur and one of the best-known members of the hadrosaur family.  The research on its unique skull has helped scientists better understand how vocalization may have played a key role in helping herds of dinosaurs effectively communicate.