Answer: ceratopsians

AnswerCrossword Clue
ceratopsiansCERATOPSIAN, a bird-hipped, plant-eating dinosaur of the late Cretaceous
ceratopsiansA gregarious quadrupedal herbivorous dinosaur of a group found in the Cretaceous period, including triceratops. It had a large beaked and horned head and a bony frill protecting the neck