Cerapod

The Cerapods are a sub-order of the Ornithischia. They are all herbivorous dinosaurs. They have thicker enamel on the inside of their lower teeth. The teeth wear unevenly, and this allows them to browse on tough vegetation.

They are divided into three groups:
Ornithopoda: including the duck-billed dinosaurs.
Pachycephalosauria: the thick-headed dinosaurs.
Ceratopsia: the horned dinasaurs.