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John Hollenhorst, Deseret News
Paleontologists work at a 20-acre site known as Doelling's Bowl on Saturday, Oct. 28, 2017. The site is about 7 miles south of I-70, just outside the northeast corner of Arches National Park. Scientists most recently have been excavating a small iguanodon. They use jackhammers, spikes and chisels to expose the fossils. Then they cover the bones with plaster and burlap to protect them for future studies in the lab.

ARCHES NATIONAL PARK — Scientists have announced the discovery of yet another new species of dinosaur in southeastern Utah.

The extinct creature's fossilized skeleton is impressive for its enormous size but also because it suggests an ancient connection between Utah and — of all places — Spain.

It was found in 2010 and dug up over several years in a remote patch of desert that has already produced countless dinosaur bones.

"Yeah," said Jim Kirkland, state paleontologist. "Probably hundreds, maybe — who knows? — thousands of skeletons."

The 20-acre site, known to paleontologists as Doelling's Bowl, is about 7 miles south of I-70, just outside the northeast corner of Arches National Park. Scientists identified the new species, called Mierasaurus, after several years of study at Salt Lake laboratory.

Scientists most recently have been excavating a small iguanodon. They use jack hammers, spikes and chisels to expose the fossils. Then they cover the bones with plaster and burlap to protect them for future studies in the lab.

On a recent dig the scientists had assistance from volunteers.

"I just love being out here," said Wendy Sears, a volunteer from Utah Friends of Paleontology. "I love being in the field. All the time, every day, it's new discoveries, new adventures. And it's exciting stuff."

Paleontologists had already been making discoveries at Doelling's Bowl for several years when stormwater ripped through a dry wash.

"The flash flood exposed some bones right along the side of the wash," Kirkland said. "That was in 2010."

What they found was the skeleton of a creature the size of a bus.

"This animal's probably on the order of 40, 45-foot long," Kirkland said.

The nearly complete skeleton includes leg bones that are 3 ½-feet long.

Scientists announced their findings in a paper published online earlier this month by the journal Nature. Their conclusion is that Mierasaurus is a previously unknown species — a giant plant-eater stuck in the mud — at least 130 million years ago.

Along with the Mierasaurus bones, scientists found a huge tooth from a meat-eating dinosaur. It suggests that a big predator attacked the Mierasaurus after it got mired in the mud.

"This animal might have been trapped in here for a week or more before it finally met its fate," Kirkland said as he walked the discovery site in Doelling's Bowl.

What makes the new species especially interesting is its ancestry: It implies a surprising geographic connection between Utah and Spain.

A Spanish paleontologist working at the site noted similarities to dinosaurs found in Spain, and that turned out to be the key to understanding Mierasaurus's history.

"He's the expert," Kirkland said. "I would never have made the link because it's not a group that we have in North America, and it's not a group of animals I had ever physically seen, you know, face-to-face before."

Mierasaurus' ancestors evidently migrated to the land mass that became Utah long after the Atlantic Ocean started opening between Europe and North America. Perhaps sea levels dropped, temporarily creating a land bridge for dinosaurs to cross between the new continents.

"They probably would have had to do a little island-hopping to get over," said Don DeBlieux of the Utah Geological Survey.

It's a controversial theory because many scientists believe Europe and North America were fully separated significantly earlier than the Utah discovery implies. But Kirkland said he's seen other evidence to support the finding.

"Oh, I think it's conclusive. We have some other stuff I can't talk about yet," he said with a chuckle. "We've got some other papers coming out and other new animals that also have ties to Europe and North Africa."

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Kirkland named Mierasauraus after Don Bernardo Miera, a cartographer and scientist who accompanied the Spanish priests Dominguez and Escalante on their famous expedition into Utah in 1776.

Kirkland said he believes it's appropriate to honor Miera by putting his name on a dinosaur.

"You know, it's a perfect link," he said with a laugh. "Two Spanish invaders into Utah."

The two visitations were incredibly distant from one another in time, however. The Spanish explorers arrived more than 1 million centuries after Mierasaurus.