‘Superbly preserved’ tubular crested dinosaur skull found in New Mexico

Scientists have found a “ perfectly preserved ” skull of a species of herbivorous dinosaur in New Mexico, known for its bizarre headgear.

The skull belongs to the iconic tubular crested dinosaur Parasaurolophus, which lived during the Late Cretaceous period, around 76.5 million to 73 million years ago.

Parasaurolophus were herbivorous reptiles that sported trumpet-shaped nasal passages into which they blew air through the so-called tube on their heads.

This particular skull belonged to a particular species of the genus Parasaurolophus – Parasaurolophus cyrtocristatus.

The newly revealed specimen is said to have been around 20 feet long (6.1 meters) and around 7.5 feet tall at the hip (2.3 meters) at the time.

Despite its extreme morphology, the details of the specimen show that the ridge is shaped much like the ridges of other related duck-billed dinosaurs.

The Parasaurolophus lived in lush subtropical floodplains in one of two ancient landmasses that once included North America, separated by a body of water 2,000 miles long.

He lived with other crested duck-billed dinosaurs, horned dinosaurs and primitive tyrannosaurs alongside many emerging and modern groups of alligators, turtles, and plants.

“My jaw dropped when I first saw the fossil,” said Professor Terry Gates, a paleontologist at North Carolina State University.

“I have been waiting for almost 20 years to see a specimen of this quality.

Imagine your nose growing up over your face, three feet behind your head, then turning around to focus above your eyes.

“The parasaurolophus was breathing through eight feet of hose before the oxygen reached its head.

The partial skull was discovered in 2017 by Erin Spear of the Smithsonian Tropical Research Institute while exploring the badlands of northwestern New Mexico, but is only now described by scientists.

Located deep in the Bisti / De-Na-Zin Desert in New Mexico, only a tiny portion of the skull was visible on a steep sandstone slope.

“ The preservation of this new skull is spectacular, finally revealing in detail the bones that make up the crest of this incredible dinosaur known to almost every dinosaur-obsessed child, ” said Joe Sertich, dinosaur curator at the Denver Museum of Nature and Science.

“This only reinforces the importance of protecting our public lands for scientific discovery.”

Museum volunteers led by Sertich were surprised to find the ridge intact as they carefully chiseled the specimen into the sandstone.

Among the most recognizable dinosaurs, the Parasaurolophus sported an elongated tube-shaped crest on its head containing an internal network of airways.

“ For the past 100 years, ideas about the exaggerated tube ridge have ranged from snorkels to super sniffers, ” said David Evans, Temerty Chair in Vertebrate Paleontology and Vice President of Natural History at the Museum. Royal Ontario.

“But after decades of study, we now believe these ridges primarily functioned as sound resonators and visual displays used to communicate within their own species.

Abundant bone fragments at the site indicated that much of the skeleton may have been preserved on an ancient sand bar, but the partial skull, part of the lower jaw, and a handful of ribs survived. to erosion.

“This specimen is truly remarkable in its preservation,” said Evans, who has worked on the Parasaurolophus dinosaur for nearly two decades.

“He answered long-standing questions about how the ridge is constructed and the validity of this particular species. For me, this fossil is very exciting.

Today, the badlands of northwestern New Mexico are dry and sparsely vegetated, a dramatic contrast to the lush floodplains preserved in their rocks that would have been the natural habitat of Parasaurolophus.

75 million years ago, when the Parasaurolophus lived in the region, North America was divided into two landmasses by the Western Interior Seaway.

This shallow body of water ran from the Gulf of Mexico to the Arctic Ocean and divided the continent into two landmasses – East America, or Appalachians, and West America, or Laramidia. – for several million years.

Laramidia (in the west) stretched from today’s Alaska to central Mexico, hosting several episodes of mountain building in the early stages of today’s Rocky Mountain building.

These mountain building events have helped preserve various dinosaur ecosystems along their eastern flanks, some of the best preserved and most continuous on the planet.

Thanks to various fossil discoveries, three species of Parasaurolophus are currently recognized, ranging from 77 million to 73.5 million years old.

The new skull belongs to P. cyrtocristatus, previously known from a single specimen collected in the same area of ​​New Mexico in 1923 by the legendary American fossil hunter Charles H. Sternberg.

The other two recognized species of Parasaurolophus are P. walkeri (whose remains have been found in Alberta, Canada) and P. tubicen (remains of younger rocks in New Mexico).

“The original parasaurolophus species, P. walkeri, dates from 1921,” said Professor Gates.

‘Our Parasaurolophus [P. cyrtocristatus] is a different species, originally described in 1960 (but found many years before being named).

“It is therefore the first P. cyrtocristatus to be found and described in 60 years.

P. cyrtocristatus was the smallest of the three species – overall, the newly described specimen is about 75% the size of the original P. walkeri found in 1921.

P. cyrtocristatus also has the most curved crest. The other two species had long ridges with only a slight curvature.

The shorter, more curved ridge of P. cyrtocristatus may have been linked to its immaturity at death, the researchers say.

For decades, the Parasaurolophus family tree has placed the two long, straight crested species (P. walkeri from Alberta and P. tubicen from New Mexico) as the most closely related, although they are separated from over 1000 miles (1600 km) and 2.5 million years old.

This new analysis, along with information from other Parasaurolophus finds from southern Utah, suggests for the first time that all species in southern New Mexico and Utah may be more closely related than they are. are not to their northern cousin.

This matches patterns seen in other groups of dinosaurs of the same age, including the horned dinosaurs.

“This specimen is a wonderful example of amazing creatures evolving from a single ancestor,” Sertich said.

The specimen is detailed further in an article published in the journal PeerJ.