Short description

Chameleons vary greatly in size and body structure, from the less than 4" Brookesia species, to the 24" Calumma parsonii. There is even one species, thought to be unique to Malawi's Mount Mulanje, that is barely 1.5cm across when fully grown. Many have head or facial ornamentation, be it nasal protrusions or even horn-like projections in the case of Chamaeleo jacksonii, or large crests on top of their head, like Chamaeleo calyptratus. Many species are sexually dimorphic, and males are typically much more ornamented than the females.

The main things chameleon species do have in common is their foot structure, their eyes, their lack of ears, and their tongue:

Chameleons have feet that are split into two main "fingers", with a soft pad in between. These "fingers" are equipped with sharp claws to gain traction on surfaces such as bark when climbing. An interesting fact about chameleons is that they have two claws on the outside of their front foot and three on the inside, yet on the back foot this is reversed.

Their eyes are the most distinctive among the reptiles. The upper and lower eyelids are joined, with only a pinhole large enough for the pupil to see through. They can rotate and focus separately to observe two different objects simultaneously. It in effect gives them a full 360 degree arc of vision around their body. When prey is located, both eyes can be focused in the same direction, giving sharp stereoscopic vision and depth perception.

They lack a vomeronasal organ. Like snakes, they don't have an outer or a middle ear and seem to be deaf; at least they cannot detect airborne sounds. But some, maybe all, can communicate via vibrations that travel through solid material like branches.

Chameleons have incredibly long tongues (sometimes longer than their own body length) which they are capable of extending out of the mouth at a rapid rate. It has a sticky tip on the end which serves to catch prey items that they would otherwise never be able to reach with their lack of locomotive speed. The tongue's tip is a bulbous ball of muscle, and as it hits its prey, the tongue rapidly forms a small suction cup. Once the tongue sticks to a prey item, it is drawn quickly back into the mouth, where the chameleon's strong jaws crush it and it is consumed. Even a small chameleon is capable of eating a large locust or mantis.