Spectacular Armored Dinosaur Found in Imperiled National Monument

The new species lived in what's now southern Utah more than 75 million years ago.

MORE THAN 75 million years ago, a plant-eating armored dinosaur lived and died on a lost continent called Laramidia. Now, its remains have been found in southern Utah—in one of the national monuments the Trump Administration is attempting to shrink.

In a study published on Thursday in PeerJ, paleontologists named a new ankylosaurid species, Akainacephalus johnsoni (“Johnson's thorny head”) from fossils found in Utah's Grand Staircase-Escalante National Monument. The remains consist of the animal's skull and parts of its skeleton, including its tail club. The dinosaur's most distinctive feature: bony knobs dotting its skull that resemble pyramids.

The dinosaur lived and died on a continent that no longer exists. At the time, an inland sea carved off western North America into a continent all its own, which scientists now call Laramidia. The subtropical continent resembled today's Mississippi: muggy, lush, and crisscrossed by braided rivers.

Akainacephalus johnsoni, a southern Laramidian, seems to be more closely related to ankylosaurids found in Asia than to ones that lived in northern Laramidia. If so, ankylosaurids probably dispersed from Asia into Laramidia multiple times, fanning out across the lost continent to form distinct populations in the north and south.

Researchers also used the discovery to recognize the hard work of fossil preparers, who painstakingly free bones from the rock encasing them. The animal's species name honors Randy Johnson, the volunteer fossil preparer at the Natural History Museum of Utah who spent thousands of hours cleaning up the dinosaur's skull and lower jaw.

Life reconstruction (closeup) of the new armored dinosaur Akainacephalus johnsoni.

ILLUSTRATION BY ANDREY ATUCHIN, COURTESY THE DENVER MUSEUM OF NATURE & SCIENCE

“It was not until the fossils came back to the museum and Randy Johnson prepared the skull that we knew we had a truly unique animal,” study leader Jelle Wiersma, a Ph.D. candidate at James Cook University, says in an email.

Fossil-Rich Monuments Being Downsized

The find draws attention to the rich fossil record in southern Utah's national monuments, Grand Staircase-Escalante and Bears Ears, even as the Trump Administration is trying to shrink the two monuments by 46 and 85 percent, respectively, in an unprecedented reversal of public land protections.

The site that yielded Akainacephalus still lies within Trump's smaller boundaries for the monument. However, the shrunken borders would exclude older deposits nearby known to contain fossils of marine reptiles and horned dinosaurs.

The broader area containing Akainacephalus, called the Kaiparowits Plateau, is at the center of a tug-of-war between paleontologists and mining interests. The million-acre area contains rich fossil beds and some 62 billion tons of coal. Scientists fear that if these lands fall under a less restrictive form of management, irreplaceable fossils could be destroyed before they're even recognized.

“The addition of Akainacephalus johnsoni [to Grand Staircase-Escalante] demonstrates the importance that we protect these invaluable paleontological resources for both scientists and the general public alike,” Wiersma says. “Citizens of the United States and the rest of the world have the right to learn and enjoy the knowledge and importance of these new fossil discoveries.”

To that end, the Society of Vertebrate Paleontology sued the Trump Administration in December 2017 over the monuments' rollback. The group's case has since been combined with lawsuits filed by environmental groups and local Native American tribes. This joint lawsuit is ongoing.

Lead Image: Randy Johnson, a paleo volunteer at the Natural History Museum of Utah, carefully prepares a fossil at the museum in Salt Lake City. NHMU/Mark Johnston

PHOTOGRAPH BY MARK JOHNSTON, THE NATURAL HISTORY MUSEUM OF UTAH IN SALT LAKE CITY

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