True chameleons include the following genera: Archaius, Bradypodion, Brookesia, Calumma, Chamaeleo, Furcifer, Kinyongia, Nadzikambia, Palleon, Rhampholeon, Rieppeleon and Trioceros.
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.
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.
Pygmy chameleons are sometimes referred to as False Chameleons. This term is actually incorrect and is in reference to anoles, particularly the Cuban False Anole.
Some chameleons play dead to avoid predation; this is called thanatosis.
The chameleon tongue accelerates towards its target at over 1642m per second. Chameleons rarely miss their intended food item.
The word Calumma comes from the Latin word for covering. This genus consists of chameleons from Madagascar with occipital lobes.
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.
Furcifer labordi (Labord’s Chameleon) has the shortest lifespan of only 4-5 months. It also has the shortest lifespan of any tetrapod!
There are currently 202 recognized chameleon species and 85 of them are found on the island of Madagascar.