CHANGELING CHAMELEON Chameleons or chamaeleons are a distinctive and highly specialized clade of Old World lizards with 202 species described as of June 2015. These species come in a range of colors, and many species have the ability to change colors. Changing skin color is an important part of communication among chameleons. A chameleon's skin changes colors in response to its emotions, such as anger or fear, changes in light, temperature or humidity. Lizards typically have feet and external ears, while snakes lack both of these characteristics. However, because they are defined negatively as excluding snakes, lizards have no unique distinguishing characteristic as a group. Lizards and snakes share a movable quadrate bone, distinguishing them from the sphenodonts, which have more primitive and solid diapsid skulls. Many lizards can detach their tails to escape from predators, an act called autotomy. Vision, including color vision, is particularly well developed in most lizards, and most communicate with body language or bright colors on their bodies, as well as with pheromones. Sight is very important for most lizards, both for locating prey and for communication, and, as such, many lizards have highly acute color vision. Most lizards rely heavily on body language, using specific postures, gestures, and movements to define territory, resolve disputes, and entice mates. Some species of lizards also use bright colors, such as the iridescent patches on the belly of Sceloporus. These colors would be highly visible to predators, so are often hidden on the underside or between scales and only revealed when necessary. The particular innovation in this respect is the dewlap, a brightly colored patch of skin on the throat, usually hidden between scales. When a display is needed, a lizard can erect the hyoid bone of its throat, resulting in a large vertical flap of brightly colored skin beneath the head which can be then used for communication. Anoles are particularly famous for this display, with each species having specific colors, including patterns only visible under ultraviolet (UV) light, as many lizards can see UV light. Lizard tails are often a different and dramatically more vivid color than the rest of the body so as to encourage potential predators to strike for the tail first. Many lizard species (including geckos, skinks, and others) are capable of shedding part of their tails through a process called autotomy. This is an example of the pars pro toto principle, sacrificing "a part for the whole", and is employed by lizards to allow them to escape when captured by the tail by a predator. The detached tail writhes and wiggles, creating a deceptive sense of continued struggle, distracting the predator's attention from the fleeing prey animal. The lizard will partially regenerate its tail over a period of weeks.
KARL THE CHAMELEON (pano/horizontal)
KARL THE CHAMELEON (square version)
