Discovery of major dinosaur fossil at Bisti helps unlock 75 million-year-old mystery
Long-extinct creature described as 'one of the weirdest animals that ever evolved'
- The fossilized skull of a Parasaurolophus cyrtocristatus was discovered at the Bisti/De-Na-Zin Wilderness in 2017.
- It was only the second specimen of that particular species ever located.
- The discovery was announced on Jan. 25 in the scientific journal PeerJ.
FARMINGTON — As the late Han Solo once famously asked, just a tad indelicately, "Where did you dig up that old fossil?"
Had that question been directed at Joe Sertich, the curator of dinosaurs at the Denver Museum of Nature & Science, he'd have a precise answer for the swashbuckling reluctant hero of "Star Wars" fame.
Sertich led a team that discovered and retrieved an approximately 75 million-year-old dinosaur skull from the Bisti/De-Na-Zin Wilderness south of Farmington in 2017.
When the discovery was announced on Jan. 25 in the scientific journal PeerJ, it set off more than a few ripples in the scientific community. The well-preserved skull of the Parasaurolophus cyrtocristatus that Sertich and his team found ranks as a highly significant specimen for a variety of reasons.
"The reception has been really good, especially from the paleontology community, which is what we hoped for," said Terry Gates, the paleontologist and assistant teaching professor at North Carolina State University who served as the lead author of the PeerJ article.
It's not hard to understand why the fossil's discovery has become such a big deal. This is only the second time a Parasaurolophus cyrtocristatus fossil has been discovered. The first time was nearly a century ago — in 1923 in the same region of New Mexico, according to a press release from the Denver Museum of Nature & Science.
But Gates doesn't mince words when it comes to explaining why the more recent discovery has captured the imagination of the paleontology and dinosaur-enthusiast community alike. The Parasaurolophus cyrtocristatus, as Gates puts it, was simply bizarre looking.
"The Parasaurolophus cyrtocristatus is totally awesome," he gushed in a decidedly unscientific, Jeff Spicoli-like burst of enthusiasm. "I think it is one of the weirdest animals that ever evolved."
Sertich isn't quite as colorful in his assessment of the species as his colleague. But he is no less emphatic about its oddness, noting that it had become a favorite of dinosaur lovers even before anyone knew what its head really looked like.
"This is an iconic dinosaur," he said.
From super sniffers to fire breather
The first Parasaurolophus cyrtocristatus fossil that was discovered, which now resides at the Field Museum in Chicago, featured a nearly complete, well-preserved skeleton, Gates said. Unfortunately, its skull had been exposed to the elements for a long time, and virtually nothing remained of it.
That has always struck Gates, who has devoted his career to researching the species, as nothing short of a tragedy.
"Once it's gone, it's gone forever," he said. "Every single time a piece gets chipped off, that information disappears into the universal ether."
But scientists had enough material on their hands to know they had encountered something beyond the pale. The specimen clearly was part of the duckbilled Parasaurolophus group, a dinosaur species that sported a long, tube-like crest on its head featuring an internal network of airways, according to the press release from Sertich's museum.
That discovery set off a century-long debate among paleontologists about how the Parasaurolophus cyrtocristatus was put together — and why it evolved that way, Gates said. It was only with the 2017 discovery of the new specimen's skull that those questions began to be answered, he said.
Numerous theories about the purpose of the dinosaur's exaggerated tube crest have arisen over the years. Terry Evans, the Temerty Chair in vertebrate palaeontology and vice president of natural history at the Royal Ontario Museum, stated in the press release that some scientists believed the tube crest served as snorkels or even "super sniffers."
Gates goes even further, explaining he has heard wild theories that the Parasaurolophus cyrtocristatus breathed fire out of the apparatus, which would have made it a dragon-like creature.
But over time, Evans said, scientific belief has coalesced behind the idea that the crests served as sound resonators and visual displays that the dinosaur used to communicate with other members of its species.
Sertich describes the crests as an "acoustic amplifier," noting that the volume of the sound likely increased as it traveled up the tubes.
How they found it
In May 2017, Sertich was leading a team of more than a dozen volunteers from the museum on an extended fossil-hunting excursion through the Bisti, a federally designated wilderness site managed by the Bureau of Land Management. It consists of approximately 45,000 acres of badlands noted for its otherworldly landscapes, near-complete lack of vegetation and the prized dinosaur fossils that get pried out of its sandstone formations with regularity.
Sertich said his team had been at the search for several days and was nearing the end of its trip with nothing of note to show for its efforts. An air of resignation had begun to settle over the group, a gloomy feeling made worse by the fact that, despite the late-spring date, it had snowed that morning, leading the fossil hunters to get a late start.
The next several hours unwound without incident, giving every indication of leading to another fruitless day. But one member of the team — Sertich's wife, Erin Spear, who is a Smithsonian ecology fellow — had gone off by herself, and at around 4 p.m., she spied a small piece of what appeared to be a bone protruding from a cliff. The rest of the team quickly joined her at the site, taking note of her discovery.
"She's one of my best fossil hunters," Sertich said of his wife, describing the site as very subtle, something that easily could have been overlooked by a less-experienced observer.
Sertich realized it was too late in the day to begin the excavation process, so he and his team wrapped up the discovery to protect it from the moisture and left it until the next morning, when they would begin to gently chisel it from the brilliant white sandstone in which it was embedded.
Sertich and his team had only two more days in the Bisti before they were scheduled to pull out, so when they returned to the site the next day to begin removing the fossil, it was with a sense of urgency. Sertich said his volunteers didn't have to make much of a disturbance in the relatively soft sandstone to uncover the fossil, but it is nevertheless delicate work, and he said it wasn't long before the workers hit bone where they weren't expecting to. That let them know they had encountered a sizable specimen, not just a few bone fragments.
As the discovery emerged from the rock over two days, it began to take shape. Sertich said it became apparent that what his team was looking at was roughly the size and shape of a donkey's head. And that signaled to them that they had stumbled across a member of the Parasaurolophus family, which includes only three known species. One of those species is the exotic Parasaurolophus cyrtocristatus, known only for that single fossil that had been recovered nearly a century earlier.
"We knew they were out there," Sertich said, referring to the existence of more Parasaurolophus cyrtocristatus fossils. "It was just a matter of time before they're found."
When the members of Sertich's team realized what they had discovered, they could scarcely believe their good fortune.
"There was definitely lots of jubilation," he said. "There were celebrations and lots of jumping around when we saw those tubes. … We were totally blown away. But suddenly, we were under a lot of pressure to get it out of the ground before the next storm came through."
Once the specimen had been removed from the cliff face, Sertich's team covered it in plaster and moist wrappings to protect it. The fossil was taken to Denver, where, for the next year, researchers worked to clean it and prepare it for closer observation.
'The answers just came to me'
Gates didn't get his first look at the specimen until March 2019, when he journeyed to Denver at the invitation of Sertich. The two had been graduate students together at the University of Utah, and Sertich knew that Gates had spent most of his career as one of a handful of paleontologists who had devoted themselves to studying Parasaurolophus cyrtocristatus. That made him a natural choice to join the Denver museum's research team.
Gates was dumbfounded by what awaited him.
"I could not believe it. I had been studying these things for 20 years," he said, but with the only known fossil in existence missing its skull, Gates and others could only speculate about the actual construction of the creature's head.
That changed instantly when he got his first look at the new fossil.
"As soon as I finally saw this thing, all the answers just came to me," he said.
Sertich said the skull was so well preserved it essentially ended all debate about the Parasaurolophus cyrtocristatus' most interesting physical feature.
"People had speculated for decades, but this was that roadmap that showed us exactly how it was constructed," he said.
Gates said the new fossil not only provided much-needed answers about the nature of Parasaurolophus cyrtocristatus. It also helped researchers fill in the blanks surrounding other members of the Parasaurolophus family for which fossils have been discovered.
"This helped solve that puzzle," he said. " … We needed this piece of the puzzle to fit those other ones in."
Gates acknowledged he was surprised by what he saw when he began to closely examine the skull, but he said the differences were so small, they don't mean much to the casual observer.
"What's really exciting to me is boring to most people," he said. "It did not meet my expectations. We're talking about things like the angles of certain bones or how broad a bone is compared to another bone. … That kind of subtle stuff, it takes years and years of observation to identify the things that are different."
This is how Gates describes the face of the Parasaurolophus cyrtocristatus: "Imagine your nose growing up your face, three feet behind your head, then turning around to attach above your eyes. Parasaurolophys breathed through eight feet of pipe before oxygen ever reached its head," he stated in the press releases from the museum.
Many of the dinosaur's other characteristics already were well known through the discovery of the previous fossil and fossilized footprints. Parasaurolophus cyrtocristatus was an herbivore and reached lengths of 30 feet.
"It was giant, crazy huge," Gates said. "I don't know what they were feeding on down there, but they were some big dinosaurs."
The ancient Bisti that the Parasaurolophus cyrtocristatus called home was a much different place than it is today, when it resembles a lunar landscape. Gates described it as a warm, moist, lush environment, comparable to the modern-day Mississippi delta, and perhaps even bordering an inland sea. He said it likely featured plenty of pine, deciduous and magnolia trees, as well as ferns and sago palms.
"It had to have a lot of plants," he said. "These were huge animals, and the best evidence suggests they traveled in herds."
Sertich said plans call for subjecting the Parasaurolophus cyrtocristatus fossil to a CT scan soon so that researchers will have three-dimensional, internal imaging of it without having to harm the specimen.
"We can really look inside the bones and test out our hypotheses about how they were used, especially the hypotheses about they were used to amplify sound," he said.
When that imaging is done, he said, they will be able to generate a computer model of the creature's head or even use a 3D printer to create a physical representation of it. At that point, researchers could come up with a computer model of what Parasaurolophus cyrtocristatus sounded like or even force air through the 3D-printed version to simulate its "voice."
Sertich said it is likely that the orientation and diameter of the creature's tubes changed as it matured, going from tightly wound to looser, thus influencing the pitch.
So, like adolescent boys, their voices may have changed as they got older?
"Exactly," Sertich said, laughing. "Puberty changed the sound."
Discoveries waiting to be found?
Not all questions about the Parasaurolophus cyrtocristatus have been answered by the most recent discovery. Gates said gaps in the fossil record and the fact that only two specimens have been located so far make it impossible to know what the animal's range was, how long it survived or how large its population was.
"We can't really make that conclusion," he said. "A large part of the land (where researchers would like to hunt for other fossils) is Native American land, and to get access to that is difficult. There potentially are lots of them out there. I believe there are a lot of specimens in the ground, but to locate them would be incredible to paleontologists. What we need is lots more cooperation between paleontologists and tribes."
Sertich emphasized that since the discovery was made on BLM land, the find does not belong to any individual or institution, but rather the people of the United States.
He said that makes clear how important it is to protect public lands, which he compared to natural laboratories and described as repositories for scientific discoveries. The fossil-rich terrain of the Four Corners is also part of the natural heritage of the Navajo Nation and Puebloan peoples, he said.
The publication of the PeerJ article has brought Sertich and his institution a good deal of media attention, and he said his work on the discovery easily ranks as one of the highlights of his career, a sentiment echoed by Gates.
The special nature of the discovery is something neither man takes for granted, especially since they don't know when a breakthrough like this will happen again.
"It might be another 100 years before the next version of this skull is found," Sertich said. "I hope not, but it's possible."
Mike Easterling can be reached at 505-564-4610 or firstname.lastname@example.org. Support local journalism with a digital subscription.