Cranial kinesis is the term for significant movement of skull bones relative to each other in addition to movement at the joint between the upper and lower jaw. It is usually taken to mean relative movement between the upper jaw and the braincase. Most vertebrates have some form of kinetic skull.
Lizards and snakes have a kinetic skull with joints in front of the braincase and at several other points to increase the gape and ability to manipulate prey. Like amphibians, lepidosaurs are ectothermic and regulate body temperature by acquiring heat from the environment. Lepidosaurs reproduce by oviparity, ovoviviparity or viviparity. Lepidosaurs
mobility of the skull allows aquamates to seize and manipulate prey and also increases te force of te bite.
snakes show the most extreme development of the kinetic skull and are capable of swallowing prey several time their own diameter