This strange dinosaur with bladelike horns roamed ancient Montana

Newly described Lokiceratops rangiformis boasted an ornate frill unlike that of any other horned dinosaur—but some scientists doubt that it is a novel species

The horned dinosaur Lokiceratops rangiformis inhabited the wetlands of what is now Montana 78 million years ago.FABRIZIO LAVEZZI/EVOLUTIONSMUSEET, KNUTHENBORG

About 78 million years ago, a peculiar-looking dinosaur roamed the swamps and wetlands of what is now Montana. The huge plant eater boasted a splendid frill on its head, topped with spikes and two large horns which curved downward like blades. Two more horns jutted out from above its eyes. The dinosaur, described for the first time today in PeerJ, is so distinctive that researchers have declared it a new species and given it a name: Lokiceratops rangiformis, after the blade-wielding Norse god Loki.

But some scientists say the dinosaur could simply be a particularly ornate example of a previously described species. “It’s an interesting-looking animal,” says Jordan Mallon, a paleontologist at the Canadian Museum of Nature who was not involved in the study. “I think it’s going to be a little contentious as to whether it represents a new species or not.”

The dinosaur’s skull and parts of its skeleton were discovered in 2019 in a Montana quarry, 3.6 kilometers south of the Canadian border, by commercial fossil hunter Mark Eatman. The Evolution Museum in Maribo, Denmark, bought the fossil pieces in 2021 and commissioned an international team of researchers to collaborate with the company Fossilogic to prepare, mount, and study the specimen in Utah.

When the team of researchers received the skull, it was in a lot of pieces. “One of the big challenges was just putting it back together in the first place,” says Joseph Sertich, a paleontologist at the Smithsonian Tropical Research Institute and co-author of the new study. “And that took several months.”

An analysis of the fossil showed it belonged to the ceratopsids, as the horned dinosaurs are known, and was one of the largest of its kind in the region. The team estimates that it was 6.7 meters long and weighed 5 tons. Compared with other ceratopsids, L. rangiformis lacks a nose horn, and its snout is lower and longer. Its ischium, a pelvic bone, has a strong kink in it, compared with the more bananalike ischium from other fossils. And its frill was unlike any described so far: Not only did it sport two large, curved horns, it also boasted two spikes in the middle, one longer than the other. This convinced the team members they were looking at a new species.

L. rangiformis would have lived alongside four other horned dinosaur species previously discovered in this region. These dinos look very similar but have distinct variations in their frills, which researchers believe were either used by males to attract females, like some modern birds do, or as a way to recognize individuals of the same and other species. The authors say the discovery provides yet more evidence that the area supported much more animal diversity than previously thought. Thanks to a boom in fossil finds, the number of known horned dinosaur groups in western North America has increased significantly the past 30 years, Sertich says. “And that number is going to only continue to grow.”

But Mallon is skeptical that five species of massive plant eaters could coexist in such a small region of what is now Montana and western Canada. The ceratopsids vary mostly in their frill patterns and not so much in feeding adaptations, he says: “Their jaws and teeth are more or less built the same way.” If the region did indeed support that much diversity, he says, you would expect the animals to be feeding on different types of plants to avoid competition. He says the dinosaurs may have belonged to just one or two species instead, with individual animals sporting unique frills. Other research has found significant differences in the headgear of dinosaurs within the same species.

The reconstructed skull of Lokiceratops rangiformis is now on display at the Museum of Evolution in Maribo, Denmark.MUSEUM OF EVOLUTION/MARIBO DENMARK
“The jury’s out,” Mallon says, “but there’s no denying that [L. rangiformis] looks very similar to other species that we’re already familiar with.”

Elizabeth Freedman Fowler, a dinosaur paleontologist at Dickinson State University who was not involved in the study, agrees some of these supposedly distinct fossils could actually be different-looking specimens of the same species.

She also questions the methods used to collect the fossils. Eatman’s team plucked the bones from the sediments and superglued some of the pieces together. They only used so-called plaster jackets—widely used to protect fragile bones—to transport two of the fossils; they wrapped the rest in aluminum foil.

“I had a little bit of an internal heart attack when I read [these details] in the paper,” Freedman Fowler says. “That is not good practice, … that’s not a responsible collecting method.” Some of the bones might have broken, she says, and precious information about the new specimen might have been lost forever.

“Removing bones from the ground without proper field techniques is still a problem with many commercial and noncommercial paleontologists,” Sertich acknowledges. However, it is fortunate this specimen did not end up lost to science and the global public, he says, given that many fossils in the United States end up in the hands of private collectors.

The fact that researchers are finding all these horned dinosaur species is a source of excitement, Mallon says—but also a source of frustration, given the discussions over each new fossil. “We’ve barely got a handle on the material that we’ve found so far,” he says. “So the debate rages on.”