Skull of Tube-Crested Dinosaur Reveals Evolution of Bizarre Crest

A newly discovered dinosaur skull helped scientists understand the differences between species of Parasaurolophus — and may have finally revealed the purpose of the creature’s unique facial crest.

Parasaurolophus group being confronted by a tyrannosaurid in the subtropical forests of New Mexico 75 million years ago. (Artwork by Andrey Atuchin / Denver Museum of Nature & Science)

(CN) — An exceptionally well-preserved skull from the duck-billed dinosaur species Parasaurolophus was recently uncovered — the first such skull found in 97 years — and may shed new light on this famous facial feature.

Parasaurolophus, a massive herbivore known for its iconic tube-crested nose, roamed North America around 75 million years ago. If you can’t recall what a Parasaurolophus looks like, any nearby child will be thrilled to fill you in.

Researchers describe this important skull in a study published Monday in the journal PeerJ, which they hope will answer some longstanding questions surrounding the evolution of this species.

“This specimen is a wonderful example of amazing creatures evolving from a single ancestor,” said Joe Sertich, curator of dinosaurs at the Denver Museum of Nature & Science and the leader of the team that discovered the specimen, in a related statement.

This hollow, tube-like crest on the dinosaur’s head contained an inner network of airways, the purpose of which has remained a mystery until recently. Scientists now believe this unique crest acted as a sort of trumpet-like communications device but may have also served as plumage.

“Over the past 100 years, ideas for the purpose of the exaggerated tube crest have ranged from snorkels to super sniffers,” explained David Evans, the Temerty chair in vertebrate paleontology and vice president of Natural History at the Royal Ontario Museum, in a related statement. “But after decades of study, we now think these crests functioned primarily as sound resonators and visual displays used to communicate within their own species.”

Scientists currently recognize three individual species of Parasaurolophus from the late Cretaceous period between 73.5 and 77 million years ago. They are believed to have inhabited territory ranging from modern-day Alberta, Canada, all the way down to New Mexico.

For over half a century, paleontologists have differentiated species of Parasaurolophus based on the shape of their crested noses. However, because those crests changed dramatically over the course of the animal’s lifespan, and a complete series of fossils spanning a single species’ lifetime has never been found, it’s been difficult to determine exactly what differences existed between species.

“My jaw dropped when I first saw the fossil,” said Terry Gates, a paleontologist from North Carolina State University, in a related statement. “I’ve been waiting for nearly 20 years to see a specimen of this quality. Imagine your nose growing up your face, three feet behind your head, then turning around to attach above your eyes. Parasaurolophus breathed through eight feet of pipe before oxygen ever reached its head.”

The skull, originally discovered in 2017 while scientists explored the New Mexican badlands around the Bisti/De-Na-Zin Wilderness, unlocked valuable new insights into the evolution of this iconic dinosaur. An abundance of bone fragments scattered around the site led researchers to believe that an entire skeleton may have at one time been preserved there, but by the time a team arrived only a partial skull, lower jaw and a handful of ribs remained.

“This specimen is truly remarkable in its preservation,” said Evans, who has spent two decades studying this remarkable creature. “It has answered long-standing questions about how the crest is constructed and about the validity of this particular species. For me, this fossil is very exciting.”

Sertich said: “The preservation of this new skull is spectacular, finally revealing in detail the bones that make up the crest of this amazing dinosaur known by nearly every dinosaur-obsessed kid. This just reinforces the importance of protecting our public lands for scientific discoveries.”

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