A ‘remarkable’ new species of giant horned, plant-eating dinosaur is among the largest ever found.
Lokiceratops rangiformis, a cousin of Triceratops, was identified from a skull discovered in the ancient swamp ‘badlands’ of Montana along the USA-Canada border in 2019.
It is distinguished by several unique features, including two huge blade-like horns on the back of its frill and the absence of a nose horn.
Scientists say the skull was longer than any other dinosaur within its group, Centrosaurinae, approaching the size of later horned behemoths.
They estimate that Lokiceratops was around 6.7 metres long and weighed around five tonnes.
Like other ceratopsian dinosaurs, Lokiceratops had a mouth filled with more than 200 teeth honed into a shearing, cutting surface that could chop vegetation – including small branches.
Its distinctive horn pattern inspired its name, Lokiceratops rangiformis, meaning ‘Loki’s horned face that looks like a caribou’.
Scientists say Lokiceratops inhabited the swamps and floodplains along the eastern shore of Laramidia, the island continent representing what is now the western part of North America, more than 78 million years ago.
Lokiceratops appeared at least 12 million years earlier than its cousin Triceratops, and was the largest horned dinosaur of its time, according to findings published in the journal PeerJ.
Study co-leader Professor Joseph Sertich, a palaeontologist with the Smithsonian Tropical Research Institute and Colorado State University, said: ‘This new dinosaur pushes the envelope on bizarre ceratopsian headgear, sporting the largest frill horns ever seen in a ceratopsian.
‘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.’
Professor Sertich said Lokiceratops is the fourth centrosaurine, and fifth horned dinosaur overall.
He explained that 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 distinctive patterns of horns above their eyes and noses, on their cheeks and along the edges of their elongated head frills.
Fossils recovered from the region suggest horned dinosaurs were living and evolving in a small geographic area, implying that dinosaur diversity is underestimated.
Study co-lead author Professor Mark Loewen, of the Natural History Museum of Utah and the University of Utah, said: ‘Previously, palaeontologists 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. The skull of Lokiceratops rangiformis is dramatically different from the other four animals it lived alongside.’
Co-author Dr Andrew Farke, of the Raymond M Alf Museum of Palaeontology, California, said: ‘We now recognise over 30 species of centrosaurines within the greater group of horned dinosaurs, with more like Lokiceratops being described every year.’
