Kosmoceratops: Uncovering the World’s Most Horned Vegetarian Dinosaur in Utah

You could call it the world’s horniest dinosaur. An almost complete skull of a dinosaur with two massive horns projecting from its brow and 13 bizarre horns around the head which fold back like waves, has been unearthed in the wilds of Utah.

Bones from the rib cage and hind legs of the dinosaur, Kosmoceratops richardsoni, were also found, along with two partial skulls, a leg, rib and tail bones of a second species, named Utahceratops gettyi.

Palaeontologist Mark Loewen of the Utah Museum of Natural History, who made the discoveries in Grand Staircase-Escalante National Monument (GSENM), describes Utahceratops as “a giant rhino with a ridiculously supersized head”.

When the partial skulls were combined they formed 96 per cent of a giant 2.3-metre-long skull that resembled one from the related herbivorous dinosaur triceratops – except that it was double the size.

Ornamental horns

Eric Roberts at the James Cook University, Australia, another member of the team, says the 13 horns adorning Kosmoceratops are not strong enough to be useful weaponry. They were probably used for intimidation or to attract the opposite sex, he says.

Earlier this year it emerged that many “new” dinosaur species are nothing of the sort, and are from a recognised species at different stages of development.

Alex Cook, a palaeontologist at the Queensland Museum, who was not involved in the work, says that confusion is unlikely here. The “extraordinary” shape of these skulls is “far beyond the variation seen in previously described species,” he says, particularly Kosmoceratops: “It’s just so out there.”

Tropical island

Radiocarbon dating of volcanic ash surrounding the fossils revealed that these plant-eating dinosaurs lived around 76 million years ago. At this time, rising sea levels flooded what is now central North America – splitting the continent and forming Laramidia, a tropical island about the size of Australia. Laramidia stretched from what is now Alberta, Canada, to New Mexico.

This region has been a honey pot for palaeontologists, who have unearthed more than a dozen new dinosaur species here, including the duck-billed hadrosaur and raptor-like theropod, Hagryphus giganteus.

According to Roberts, many of these species are unique to the region, which might be a result of the island’s isolation for 27 million years, until it was again connected with the eastern part of what is now the US.

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