Really Horny Dinosaur Heralded from Lost Continent

Artist's rendering of two new dinosaur species -- Utahceratops gettyi (top) and Kosmoceratops richardsoni -- discovered in the Grand Staircase-Escalante National Monument of southern Utah.

(Image credit: Courtesy of Utah Museum of Natural History.)

A bizarre dinosaur with 15 horns is one of two new close relatives of Triceratops that scientists unearthed in southern Utah from lands once part of a now-lost continent.

The dinosaur, named Kosmoceratops richardsoni, had a horn over its nose, one atop each eye, one at the tip of each cheekbone, and 10 across the rear margin of its bony frill. Its head is the most ornate of any dinosaur known.

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Its larger relative, also newly discovered, is named Utahceratops gettyi – honoring Mike Getty, paleontology collections manager at the Utah Museum of Natural History, who discovered this behemoth in 2000. It possessed a large horn over the nose, and short, blunt eye horns that projected strongly to the side rather than upward, much more like the horns of modern bison than those of Triceratops and its other relatives, known as ceratopsians.

Although scientists have speculated that the ornate horns and frills of ceratopsians might have helped fight off carnivores, for the newly discovered dinosaurs "most of these bizarre features would have made lousy weapons to fend off predators," Sampson said. "It's far more likely that they were used to intimidate or do battle with rivals of the same sex, as well as to attract individuals of the opposite sex."

Back when these behemoths were alive roughly 76 million years ago, the area was part of the island continent of Laramidia, which was born when a warm, shallow sea dubbed the Western Interior Seaway flooded the central region of North America 95 million years ago. This split the eastern and western portions of the modern continent for 27 million years until sea levels fell again. Western North America formed a roughly Australia-sized continent called Laramidia, stretching from Mexico in the south to Alaska in the north, while Eastern North America was known as Appalachia.

Starting about 50 year ago, paleontologists began noticing that although they found major groups of dinosaurs all throughout Laramidia, different species of these groups appeared in the north than in the south — for example, Alberta and Montana versus New Mexico and Texas. Such provincialism seemed odd, given the small size of the continent. For comparison, there are currently five rhino- to elephant-sized mammals on the entire continent of Africa, while there may have been more than two dozen giant dinosaurs living on Laramidia, a landmass about one-quarter that size.

Apparently, some kind of barrier existed near the latitude of northern Utah and Colorado that limited the exchange of dinosaur species north and south. Perhaps there were physical barriers such as mountains or rivers, "but we have no evidence of such then," Sampson said. "That means that perhaps these areas were separated by ecology, with different plants found in both regions, which in turn would spur different sets of herbivores to evolve and then different sets of carnivores."

Many places the researchers dug at were 25 miles (40 km) from the nearest paved roads. "We often had to hike up rugged terrain, bringing in not just food and water, but jackhammers and rock-saws, as well as plaster and burlap to wrap the fossils in big protective jackets that we would get helicopters to airlift," Sampson told LiveScience. "These relatively unexplored treasure troves were exciting places to be."

In addition to Kosmoceratops and Utahceratops, scientists have unearthed a variety of other plant-eating dinosaurs in the national monument, including duck-billed hadrosaurs, such as Gryposaurus monumentensis, armored ankylosaurs, and dome-headed pachycephalosaurs. They have also dug up large and small carnivorous dinosaurs, from raptor-like predators, such as Hagryphus giganteu, to mega-sized tyrannosaurs — not T. rex, but its smaller relatives. These findings help confirm that dinosaurs living on Laramidia were divided into provinces.

Charles Q. Choi is a contributing writer for Live Science and Space.com. He covers all things human origins and astronomy as well as physics, animals and general science topics. Charles has a Master of Arts degree from the University of Missouri-Columbia, School of Journalism and a Bachelor of Arts degree from the University of South Florida. Charles has visited every continent on Earth, drinking rancid yak butter tea in Lhasa, snorkeling with sea lions in the Galapagos and even climbing an iceberg in Antarctica.