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22/09/2010

Really Horny Dinosaur Heralded from Lost Continent

A bizarre dinosaurwith 15 horns is one of two new close relatives of Triceratops thatscientists unearthed in southern Utah from lands once part of a now-lostcontinent.

The dinosaur, named Kosmoceratopsrichardsoni, had a horn over its nose, one atop each eye, one at thetip of each cheekbone, and 10 across the rear margin of its bony frill. Itshead is theknown.

The name comes fromthe Latin "kosmos" for ornate, the Greek "ceratops" meaninghorned face, and the latter part honors Scott Richardson, the volunteer whodiscovered two skulls of this animal in 2007.

"Kosmoceratopsis one of the most amazing animals known, with a huge skull decorated with anassortment of bony bells and whistles," said researcher Scott Sampson, aresearch curator at the Utah Museum of Natural History.

Kosmoceratops was perhaps 15 feet (5 meters) long andweighed about 5,500 pounds (2,500 kilograms) when alive.

Its larger relative, also newly discovered, is named- honoring Mike Getty, paleontology collections manager at theUtah Museum of Natural History, who discovered this behemoth in 2000. Itpossessed a large horn over the nose, and short, blunt eye horns that projectedstrongly to the side rather than upward, much more like the horns of modernbison than those of and its other relatives, known as ceratopsians.

Utahceratops was roughly 18 to 22 feet (6 to 7 meters)long and about 6 feet (2 meters) tall at the shoulder and hips, and overallweighed about 6,600 to 8,800 pounds (3,000 to 4,000 kilograms).

Utahceratops possessed a skull about 7 feet (2.3 meters)long, prompting researcher Mark Loewen, a paleontologist at the Utah Museum ofNatural History, to liken it to "a giant rhino with a ridiculouslysuper-sized head."

Although scientistshave speculated that the ornatehorns and frills of ceratopsians might have helped fight off carnivores, forthe newly discovered dinosaurs "most of these bizarre features would havemade lousy weapons to fend off predators," Sampson said. "It's farmore likely that they were used to intimidate or do battle with rivals of thesame sex, as well as to attract individuals of the opposite sex."

Land of the lost

These new beastswere unearthed in Grand Staircase-Escalante National Monument in southern Utah."Grand Staircase-Escalante National Monument is now one of the country'slast great, largely unexplored dinosaur boneyards," Sampson said.

Back when thesebehemoths were alive roughly 76 million years ago, the area was part of theisland continent of Laramidia, which was born when a warm, shallow sea dubbedthe Western Interior Seaway flooded the central region of North America 95million years ago. This split the eastern and western portions of the moderncontinent for 27 million years until sea levels fell again. Western NorthAmerica formed a roughly , stretchingfrom Mexico in the south to Alaska in the north, while Eastern North Americawas known as Appalachia.

Most known dinosaursfrom Laramidia were concentrated in a narrow belt of plains sandwiched betweenthe seaway to the east and mountains to the west. Utah was located in thesouthern part of the continent, and Kosmoceratops and Utahceratopslived in a swampy, subtropical environment about 60 miles (100 kilometers) fromthe seaway.

Provincial puzzle

These new dinosaursare part of a wave of discoveries made in the southern part of Laramidia thatcould help solve a mystery roughly a half-century old.

Starting about 50year ago, paleontologists began noticing that although they found major groupsof dinosaurs all throughout Laramidia, different species of these groupsappeared in the north than in the south - for example, Alberta and Montanaversus New Mexico and Texas. Such provincialism seemed odd, given the small sizeof the continent. For comparison, there are currently five rhino- to elephant-sizedmammals on the entire continent of Africa