An ancestor to the horned dinosaur Triceratops roamed the earth millions of years before its famous descendant, making it the earliest discovered member of the family, scientists say.
The newly named species, Titanoceratops, weighed in at around 15,000 pounds and had an 8-foot-long skull. The ancient dinosaur lived during the Cretaceous period, about 74 million years ago in the American Southwest.
The finding, which will feature in the journal of Cretaceous Research, suggests the triceratopsian group of dinosaurs evolved its large size five million years earlier than previously thought, according to Nicholas Longrich, the paleontologist at Yale University who made the discovery.
Longrich made the discovery by accident and was searching through scientific papers when he happened upon the description of a partial skeleton of a dinosaur discovered in New Mexico in 1941. The skeleton went untouched until 1995, when it was finally prepared and identified incorrectly as Pentaceratops, a species common to the area.
"When I looked at the skeleton more closely, I realized it was just too different from the other known Pentaceratops to be a member of the species," Longrich said in a statement.
The newly identified Titanoceratops is similar to Triceratops, but with a thinner frill, longer nose and bigger horns. Longrich, hopes the discovery of similar skeletons will help further shed light on the origins of horned dinosaurs.
"There have got to be more of them out there," Longrich said.