Coahuilaceratops , First Horned Dinosaur From Mexico

A new species of horned dinosaur unearthed in Mexico has larger horns that any other species - up to 4 feet long - and has given scientists fresh insights into the ancient history of western North America.

The 72-million-year-old rhino-sized creature - Coahuilaceratops magnacuerna - was a four- to five-ton plant-eater belonging to a group called horned dinosaurs, or ceratopsids. The name Coahuilaceratops magnacuerna (Koh-WHE-lah-SARA-tops mag-NAH-KWER-na), refers to the Mexican state of Coahuila where it was found, and to the Greek word "ceratops" meaning "horned face." The second part of the name, magnacuerna, is a combination of Latin and Spanish meaning "great horn," in reference to the huge horns above the eyes of this dinosaur.

The study, partially funded by the National Geographic Society, was conducted by Mark Loewen, Scott Sampson, Eric Lund and Mike Getty, paleontologists at the Utah Museum of Natural History. Also involved were Andrew Farke of the Raymond M. Alf Museum in Claremont, Calif.; Martha Aguillón-Martínez, Claudio de Leon and Rubén Rodríguez-de la Rosa from the Museum of the Desert in Saltillo, Mexico; and David Eberth of the Royal Tyrrell Museum of Palaeontology in Alberta, Canada.

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

Coahuilaceratops comes from a rock unit known as the Cerro del Pueblo Formation, which dates to between 71.5 million and 72.5 million years ago. The skeletons, which de Leon discovered in 2001 near the town of Porvenir de Jalpa, approximately 40 miles west of Saltillo, were excavated in 2003. The fossils then were prepared at the Utah Museum of Natural History, requiring two years of meticulous work by skilled volunteer preparator Jerry Golden.

Loewen explained that Coahuilaceratops represents the first occurrence of an identifiable species of horned dinosaur in southern Mexico. "The horned dinosaurs are an extraordinary example of vertebrate evolution," he said. They evolved and diversified on Laramidia along a thin strip of land that stretched from Alaska to Mexico. "Finding this horned dinosaur so far south in Mexico offers us a different picture of what the ancestors of Triceratops were like."