Protoceratops, (its name meaning 'First Horned Face' derived from the Greek proto-/πρωτο- meaning 'first', cerat-/κερατ- meaning 'horn' and -ops/-ωψ meaning face) was a sheep-sized (1.5 to 2m long) herbivorous ceratopsian dinosaur, from the Upper Cretaceous Period of what is now Mongolia. Unlike later ceratopsians, it lacked well-developed horns. Protoceratops had a large neck frill, which may have served to protect the neck, to anchor jaw muscles, to impress other members of the species or combinations of these functions.