Ceratopsids are instantly recognizable: a parrot-like beak for cropping tough vegetation, a bony frill extending back from the skull, and, in most genera, one or more horns over the brow or nose. The family splits into two main branches. Centrosaurines, like Styracosaurus and Centrosaurus, tend toward shorter frills and a dominant nasal horn; chasmosaurines, like Triceratops and Chasmosaurus, carry longer frills and prominent brow horns instead. Both branches shared the same dental-battery chewing system seen in hadrosaurids, letting them process fibrous Late Cretaceous plants efficiently.
Every confirmed ceratopsid comes from North America, making the family one of the more geographically restricted major dinosaur groups despite its diversity -- more than five dozen genera are currently recognized. The frills and horns have long been debated as defense against tyrannosaurs, species recognition, or both; bite marks on some Triceratops frills suggest predation attempts were a real hazard of Late Cretaceous life.