"In terms of large-bodied ones that look like Triceratops, this is definitely the oldest," said biologist Michael Ryan, lead author of the new study describing the dinosaur, published online Thursday by the Canadian Journal of Earth Sciences.

The newfound plant-eater has been named Xenoceratops foremostensis—Latin for "alien horned-face from Foremost," the small Canada town where some Xenoceratops fossils were found in 1958.

Like its more famous cousin Triceratops—which lived 15 million years later, during the dinosaurs' last days—Xenoceratops had long spearlike horns thrusting from its brow and a shieldlike frill extending back from its skull. But unlike Triceratops, Xenoceratops also had horns on its frill.

(Read about another Triceratops ancestor found in Canada.)

The new dinosaur is known