Chameleons do not have external ears or a tympanic membrane, but they do have internal ears as well as degenerated middle ears. They do not hear well but they can detect low frequency sounds.
The largest chameleon species by weight is Calumma parsonii (Parson’s Chameleon).
Chameleons have laterally compressed bodies. This enables them to warm up quickly by presenting a larger surface area to the sun. It also helps some chameleon species blend in among the similarly shaped leaves in their environment.
Chameleon fossils have been found in central Europe and China, indicating they were once much more widespread than they are now.
Chamaeleo namaquensis is found in the desert of Namibia. To cool off it will sometimes bury itself in the sand.
True chameleons include the following genera: Archaius, Bradypodion, Brookesia, Calumma, Chamaeleo, Furcifer, Kinyongia, Nadzikambia, Palleon, Rhampholeon, Rieppeleon and Trioceros.
Kinyongia uthmoelleri and Trioceros quadricornis gracilor have red claws.
Chameleons change color by rearranging a lattice of nanocrystals in one of their top layers of skin cells called iridophores. Chameleons can then stretch this layer, broadening the nanocrystalline lattice, thereby causing it to reflect a different wavelength of light.
The horns on a chameleon are made up of ringlike segments of inner bone covered by a hard keratin-like skin.