Chameleons

Skeleton of Chamaeleo ousteleti.

Chameleons are Old World lizards with distinctive casqued heads, large skin-covered eyes, and feet which lack palms or soles. The tail is generally prehensile and acts as a fifth limb for climbing. Most species are arboreal, though a few are ground dwellers.

The chameleon tongue is renowned for its great length--oven as long as the combined head-body length--and its ability to be fired at insect prey. The eyes are covered by fused lids with a small round central aperture, and each can move independently of the other (also seen in many arboreal lizards in other families). The visual acuity of chameleons is excellent, as is their 3D perception.

The eardrum is covered by skin. Dentition is acrodont (on the crest of the jaw bones).

Chameleons are well known as color changers, and many can display a great array of diversity. Others, however, have almost no color changing ability, and all are greatly exceeded in ability by octopuses and squids.