Remarkable New Dinosaur Unearthed in the Ancient Swamps of Montana

Reconstruction of Lokiceratops in the 78-million-year-old swamps of northern Montana, as two Probrachylophosaurus move past in the background. Credit: Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg

Newly discovered Lokiceratops rangiformis is among the largest and most ornate horned dinosaur ever found, with two huge blade-like horns on the back of its frill.

The newly discovered Lokiceratops rangiformis, a plant-eating dinosaur with unique, large blade-like horns and a distinctive asymmetric spike, was found in the badlands of northern Montana and lived over 78 million years ago on the island continent of Laramidia. This species, lacking a nose horn but featuring the largest frill horns ever seen, showcases the evolutionary diversity of ceratopsians, influenced significantly by sexual selection.

Discovery of Lokiceratops Rangiformis

A remarkable, new species of horned, plant-eating dinosaur is being unveiled at the Natural History Museum of Utah. The dinosaur, excavated from the badlands of northern Montana just a few miles from the USA-Canada border, is among the largest and most ornate ever found, with two huge blade-like horns on the back of its frill. The distinctive horn pattern inspired its name, Lokiceratops rangiformis, meaning “Loki’s horned face that looks like a caribou.” The new species was announced today (June 20) in the scientific journal PeerJ.

Portrait reconstructions of all four centrosaurine dinosaurs that lived together in the Kennedy Coulee Assemblage of northern Montana and southern Alberta. Credit: Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg

A Prehistoric Giant

More than 78 million years ago, Lokiceratops inhabited the swamps and floodplains along the eastern shore of Laramidia. This island continent represents what is now the western part of North America created when a great seaway divided the continent around 100 million years ago. Mountain building and dramatic changes in climate and sea level have since altered the hothouse world of Laramidia where Lokiceratops and other dinosaurs thrived.

The behemoth is a member of the horned dinosaurs called ceratopsids, a group that evolved around 92 million years ago during the Late Cretaceous, diversified into a myriad of fantastically ornamented species, and survived until the end of the time of dinosaurs. Lokiceratops (lo-Kee-sare-a-tops) rangiformis (ran-ɡi-FOHR-mees) possesses several unique features, among them are the absence of a nose horn, huge, curving blade-like horns on the back of the frill—the largest ever found on a horned dinosaur—and a distinct, asymmetric spike in the middle of the frill.

Lokiceratops rangiformis appeared at least 12 million years earlier than its famous cousin Triceratops and was the largest horned dinosaur of its time. The name Lokiceratops translates as “Loki’s horned face” honoring the blade-wielding Norse god Loki. The second name, rangiformis, refers to the differing horn lengths on each side of the frill, similar to the asymmetric antlers of caribou and reindeer.

Reconstruction of Lokiceratops surprised by a crocodilian in the 78-million-year-old swamps of northern Montana, USA. Credit: ©Andrey Atuchin for the Museum of Evolution in Maribo, Denmark

Evolutionary Insights and Ceratopsian Diversity

“This new dinosaur pushes the envelope on bizarre ceratopsian headgear, sporting the largest frill horns ever seen in a ceratopsian,” said Joseph Sertich, a paleontologist with the Smithsonian Tropical Research Institute and Colorado State University, and co-leader of the study. “These skull ornaments are one of the keys to unlocking horned dinosaur diversity and demonstrate that evolutionary selection for showy displays contributed to the dizzying richness of Cretaceous ecosystems.”

Lokiceratops rangiformis is the fourth centrosaurine, and fifth horned dinosaur overall, identified from this single assemblage. While ceratopsian ancestors were widespread across the northern hemisphere throughout the Cretaceous period, their isolation on Laramidia led to the evolution of huge body sizes, and most characteristically, distinctive patterns of horns above their eyes and noses, on their cheeks and along the edges of their elongated head frills. Fossils recovered from this region suggest horned dinosaurs were living and evolving in a small geographic area—a high level of endemism that implies dinosaur diversity is underestimated.

Fossil skull bones of Lokiceratops reconstructed and displayed at the Museum of Evolution in Maribo, Denmark. Credit: Museum of Evolution

Coexistence and Diversity in Ancient Ecosystems

“Previously, paleontologists thought a maximum of two species of horned dinosaurs could coexist at the same place and time. Incredibly, we have identified five living together at the same time,” said co-lead author Mark Loewen, paleontologist at the Natural History Museum of Utah and professor in the Department of Geology & Geophysics at the University of Utah. “The skull of Lokiceratops rangiformis is dramatically different from the other four animals it lived alongside.”

Patterns of Evolution in Horned Dinosaurs

Horned dinosaurs were more diverse than previously thought, and some groups had relatively small distributions across the island landmass of Laramidia during the Late Cretaceous.

Scientists have argued about the patterns of evolution within the group of horned dinosaurs over the years. “We now recognize over 30 species of centrosaurines within the greater group of horned dinosaurs, with more like Lokiceratopsbeing described every year,” said co-author Andrew Farke from the Raymond M. Alf Museum of Paleontology.

This study shows that centrosaurine ceratopsid species and clades were confined to small geographic areas. “The endemism present in centrosaurines is greater than in any other group of dinosaurs,” said undergraduate University of Utah student and co-author Savhannah Carpenter.

“Rapid evolution may have led to the 100- to 200-thousand-year turnover of individual species of these horned dinosaurs,” said Loewen. This rapid evolution is most consistent with sexual selection acting upon these animals.

“Sexual selection acting on the genes responsible for the horns of the frill would produce modifications to cis-regulatory elements that would express differences in the size and shape of individual frill horns producing the variations in patterns we see in these animals,” said coauthor Jingmai O’Connor of the Field Museum in Chicago.

Museum of Evolution in Maribo, Denmark. Credit: Museum of Evolution

New Dinosaur Name: Lokiceratops rangiformis

• Based on never-before-seen features, the scientific team named it a new genus and species of dinosaur, Lokiceratops rangiformis.
• The first part of the name, Lokiceratops, (lo-Kee-sare-a-tops) can be translated from Greek as ‘Loki’s horned face’ and honors the blade-wielding Norse god, Loki. The second part of the name rangiformis (ran-ɡi-FOHR-mees) translates to “formed like a caribou,” referring to the fact that the frill exhibits different lengths of horns on each side, as in the antlers of caribou and reindeer.
• Lokiceratops rangiformis is particularly notable for a pair of huge, blade-shaped horns on the back of the frill. These represent the largest frill horns ever observed on a horned dinosaur.

Size

• Lokiceratops was approximately 22 feet (6.7 meters) long.
• Lokiceratops weighed around 11,000 pounds (5 metric tonnes).

Relationships and Anatomy

• Lokiceratops belongs to a group of herbivorous dinosaurs called “centrosaurines,” the same group as the famous dinosaurs Nasutoceratops, Styracosaurus, and Pachyrhinosaurus.
• Other dinosaurs found in the same layers as Lokiceratops include the ceratopsian dinosaurs Judiceratops,Albertaceratops, Medusaceratops, and Wendiceratops, and the duck-billed dinosaur Probrachylophosaurus. They were likely preyed upon by a tyrannosaur similar to Thanatotheristes.
• Lokiceratops is closely related to Albertaceratops and Medusaceratops. All three are from the same, small geographic area.
• Lokiceratops was a four-legged herbivore, with a giant upper and lower beak, long horns above its eyes, and a meter-long frill covered with horns extending from the back of its head. It was the most massive herbivore in its ecosystem, and the largest centrosaurine ever found in North America
• Like other ceratposian dinosaurs, Lokiceratops had a mouth filled with over 200 teeth honed into a shearing, cutting surface that could chop vegetation including small branches.

Age and Geography

• Lokiceratops lived during the Campanian stage of the Late Cretaceous period, 78 million years ago.
• Lokiceratops lived in a subtropical coastal plain covered with forests, small lakes, and swamps along the east coast of Laramidia, the island landmass of western North America.
• With the exception of Sinoceratops from China, all of the ceratopsid dinosaurs like Lokiceratops are known only from Laramidia.

Discovery

• Lokiceratops was found in the badlands of northern Montana 2 miles (3.6 kilometers) south of the USA-Canada border. The quarry is located within a geologic unit known as the McClelland Ferry Member of the Judith River Formation.
• Lokiceratops was first discovered and excavated by Mark Eatman during the spring of 2019
• Lokiceratops is on display at the Museum of Evolution in Maribo, Denmark. Research quality replicas are housed at the Royal Ontario Museum in Toronto, Ontario, Canada, and at the Natural History Museum of Utah, in Salt Lake City, Utah, USA.
• These discoveries are the result of a collaboration between the National Science Foundation, the Natural History Museum of Utah, the University of Utah and the Museum of Evolution.

Fact Sheet: Major Points of the Paper

• A remarkable new species of horned dinosaur, Lokiceratops rangiformis, is described based on a recently discovered skull and partial skeleton. The specimen was unearthed in Kennedy Coulee in northern Montana along the USA-Canada border.
• Lokiceratops rangiformis is distinguished by a number of unique features, including the absence of a nose horn along with the number, pattern, and shapes of the horns along the edge of the frill. The skull was longer than any other dinosaur within its group, Centrosaurinae, approaching the size of later horned behemoths.
• Lokiceratops rangiformis is the fourth centrosaurine, and fifth horned dinosaur overall, from a single assemblage, and is closely related to two of the other animals it lived alongside.
• The analysis conducted by the study team suggests that one family of horned dinosaurs, the centrosaurines, underwent rapid evolution and lived in relatively small geographic areas along the island landmass of Laramidia.
• The high endemism seen in centrosaurines implies that dinosaur diversity is presently underestimated and not directly comparable to the large (historic) geographic ranges seen in most large mammals today.

Study Design

• Comparisons with all other horned dinosaurs reveal a distinct pattern of horns on the frill extending from the back of the skull. Unlike many related horned dinosaurs, Lokiceratops lacks a nose horn.
• Many of the comparisons were made with the thousands of bones of horned dinosaurs that are housed in the collections of the Natural History Museum of Utah, the Royal Ontario Museum, the Royal Tyrrell Museum, the American Museum of Natural History, the Smithsonian and many other institutions around the world.
• The study included the most complete analysis of horned dinosaur evolution ever conducted, producing a new hypothesis of relationships for the group.
• The study was funded by the Museum of Evolution, the University of Utah and the National Science Foundation.

Preparation and Mounting

• It required several weeks for preparators Jen Sellers and Estrella Gallegos to fully remove the matrix from the bones of Lokiceratops. The bones were reconstructed into a 3-D skull mount and each bone is removable for scientific study.
• A reproduction of the skull was used to sculpt a life-like reconstruction of the head of Lokiceratops to illustrate how the dinosaur may have appeared in life. Details of the skin of the sculpture on display at the Natural History Museum of Utah are based on known ceratopsian skin specimens from other, related dinosaurs including specimens housed in its collections.

More Information

• The Natural History Museum of Utah in Salt Lake City houses one of the world’s most important collections of horned dinosaur fossils, specimens that help paleontologists reconstruct the family tree of ceratopsians, research exhibited on its famous “Ceratopsian Wall.” These specimens form the foundation for extensive research and educational opportunities for students and scientists across the globe.
• The Museum of Evolution in Maribo, Denmark, where Lokiceratops is on display offers a unique, multisensory experience with lights, sounds and scents that bring the prehistoric world to life in a completely new and modern way. The museum actively supports scientific inquiry and houses genuine skeletons of many exquisite fossils from the Permian, Jurassic, Cretaceous and Neogene periods including a spectacularly preserved specimen of Allosaurus; the largest ceratopsian specimen in the world, a Torosaurus; the largest specimen of the North American stag moose,Cervalces; and the eighth specimen of the first bird, Archaeopteryx.

Reference: “Lokiceratops rangiformis gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs” 20 June 2024, PeerJ.
DOI: 10.7717/peerj.17224