Branchial arch

[3] These regress upon adulthood, their function taken over by the gills proper in fish, or by lungs (which are homologous to swim bladders) and cutaneous respiration in most amphibians.

Species such as snakes and monitor lizards, whose tongue has evolved into a purely sensory organ, often have very reduced hyoid systems.

The primitive arrangement is 7 (possibly 8) arches, each consisting of the same series of paired (left and right) elements.

order from dorsal-most (highest) to ventral-most (lowest), these elements are the pharyngobranchial, epibranchial, ceratobranchial, hypobranchial, and basibranchial.

The pharyngobranchials may articulate with the neurocranium, while the left and right basibranchials connect to each other (often fusing into a single bone).