Ceratopsian frill
A bony extension of a ceratopsian skull that projects behind the head. Frills varied in size and shape and could bear openings or ornamentation.
Ceratopsia: A group of herbivorous dinosaurs characterized by beaked jaws and, in many members, elaborate skull ornamentation. The frill is a defining skull feature within this dinosaur group.
Epoccipital: A discrete bony element associated with the frill margins of many ceratopsians, often fused into the adult skull. These elements formed marginal ornamentation along the frill in several ceratopsian lineages.
Ceratopsian taxonomy: The classification of ceratopsian dinosaurs using anatomical features and evolutionary relationships. Frill shape and ornamentation provide characters used to distinguish ceratopsian taxa.
Sexual selection in dinosaurs: The proposed role of mate choice and competition in shaping dinosaur traits and behavior. Frill variation has been interpreted as a possible signal used in mate choice.
Ceratopsian skull: The skull of a ceratopsian dinosaur, commonly bearing a beak, cheek regions, horns, and a rearward frill. The frill forms the rear extension of this larger skull structure.
Ceratopsian ontogeny: The growth and developmental changes of ceratopsian dinosaurs from juvenile to adult stages. Frill proportions and surface features changed substantially as ceratopsians matured.
Triceratops: A large, late Cretaceous ceratopsian dinosaur from western North America with a broad frill and three facial horns. Its broad, solid frill is among the best-known examples of ceratopsian frill anatomy.
Thermoregulation in dinosaurs: The regulation of body temperature in dinosaurs through physiological and behavioral means. Frills were once proposed as heat exchangers, a hypothesis tested against their anatomy.
Parietal bone: A paired skull bone forming much of the rear and upper surface of the skull in many vertebrates. In ceratopsians, the parietals make up much of the frill's central area.
Ceratopsian skull growth: The developmental expansion and remodeling of ceratopsian skull bones as an individual grew. Growth altered the frill's shape and the fusion of its component bones.