Neoceratopsia

Neoceratopsia is a clade of herbivorous marginocephalian dinosaurs within Ceratopsia that includes the more derived ceratopsians. It comprises Protoceratopsidae, Leptoceratopsidae, and Ceratopsidae, and excludes the more basal Psittacosauria. Fossils are known from Asia and North America, with a temporal range from the Early Cretaceous to the end of the Cretaceous, roughly 125 to 66 million years ago.

Members of Neoceratopsia typically possess beaked mouths and complex dentitions adapted for processing vegetation. Cranial ornamentation varies widely, with many ceratopsids developing large parietal frills and facial horns, while protoceratopsids and leptoceratopsids tend to be smaller and less ornamented. The group shows a trend toward increasing skull complexity and dental battery arrangements, reflecting diversification in feeding strategies and ecological roles.

The evolutionary significance of Neoceratopsia lies in its diversification of herbivorous ceratopsians after the split from more basal ceratopsians. This clade includes some of the best-known ceratopsians, ranging from the smaller, less ornamented forms to the highly derived, horned and frilled dinosaurs that dominated Cretaceous ecosystems in Asia and North America.

Notable members include Protoceratops (a protoceratopsid from Asia), Leptoceratops (a small leptoceratopsid from North America), and the large ceratopsids such as Triceratops and Centrosaurus. Together, Neoceratopsia represents a major chapter in ceratopsian evolution, highlighting the rise of cranial display structures and advanced dental systems in Late Cretaceous dinosaurs.