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Rhinoceros-sized dinosaur had horns the size of baseball bats

Unearthed in Mexico, a newly discovered species of dinosaur was found to have had horns bigger than any member of its group, including the legendary Triceratops.

By Jeanna BrynerLiveScience Managing Editor / May 28, 2010

This artist's rendering of Coahuilaceratops magnacuerna, a horned dinosaur unearthed in Mexico, shows its gigantic horns.

Lukas Panzarin for the Utah Museum of Natural History.


A tubby dinosaur sporting horns each the length of a baseball bat roamed what is now Mexico some 72 million years ago.

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Remains of the plant-eating dinosaur, now called Coahuilaceratops magnacuerna, were unearthed from the Cerro del Pueblo Formation in Coahuila, Mexico. Fossils belonging to both an adult and juvenile of the species were unearthed at the site.

When alive, the dinosaur would have been about the size of a rhinoceros, weighing 4 to 5 tons (3,600 to 4,500 kilograms), with horns estimated to be 3 to 4 feet long (about 1 meter). The horns are considered the longest of any ceratopsids, a group of plant-eating horned dinosaurs whose members include the famous Triceratops.

IN PICTURES: Fearsome dinosaurs

Like other horned dinosaurs, Coahuilaceratops probably used its headgear to attract mates and fight with rivals of the same species.

"Being one of the largest herbivores in its ecosystem, adult Coahuilaceratops probably didn't have to worry about large tyrannosaur predators," said researcher Andrew Farke of the Raymond M. Alf Museum in Claremont, Calif.

The new species, announced today, will be detailed in the book "New Perspectives on Horned Dinosaurs" to be released next week by Indiana University Press.

Monster storms

Mark Loewen, a paleontologist with the Utah Museum of Natural History and lead author of the study, described the arid, desert terrain where the dinosaur was recovered as nothing like Mexico during the Late Cretaceous (97 million to 65 million years ago). At that time, due to high global sea levels, the region was a humid estuary with lush vegetation, much like the present-day Gulf Coast.