The crest is a prominent feature exhibited by several bird and other dinosaur species on their heads. It is distinct from features such as casques and cockscombs - sometimes erroneously referred to as "crests", which are bony and fleshy structures respectively.
The grey crowned crane - an example of a crested bird species
A restoration of the dinosaur Anchiornis, showing the crest of feathers on its head
Citron-crested cockatoo crest feathers (on 1 cm grid)
Major Mitchell's cockatoo
A casque is an anatomical feature found in some species of birds, reptiles, and amphibians. In birds, it is an enlargement of the bones of the upper mandible or the skull, either on the front of the face, or the top of the head, or both. The casque has been hypothesized to serve as a visual cue to a bird's sex, state of maturity, or social status; as reinforcement to the beak's structure; or as a resonance chamber, enhancing calls. In addition, they may be used in combat with other members of the same species, in the gathering of food, or in thermoregulation.
Like most hornbills, this male great hornbill has a distinctive casque on its upper mandible.
The bony, vascularized casque of the southern cassowary helps the bird to shed excess heat.
The high casque of the veiled chameleon provides an expanded area for the attachment of jaw musculature – and may also help the animal to collect moisture or store fat.
