page_title: Lizard
section_title: Physiology
hierarchical_section_title: Lizard / Physiology
caption_attribution_description: I photographed this feral Jackson's Chameleon on the island of Maui, Hawaii. Rich Torres, Burlingame, Calif.
context_page_description: Lizards are reptiles. Together with snakes, they make up the order Squamata.
  There are about 6,000 species, which live all over the world, except in cold climates. They range across all continents except Antarctica, as well as most oceanic island chains. One type, the marine iguana, lives in the sea. Size varies greatly, from geckos of a few inches or cm to the Komodo dragon of 3 meters and 70 kg.
  Some kinds of lizard are:
  Basilisk
  Tories
  Gecko
  Iguana
  Monitor lizard
  Frill-necked Lizard
  Draco, flying lizard
  Slow-worm: a lizard without legs.
context_section_description: Sight is very important for most lizards, both for locating prey and for communication. 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 lizard also utilize 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 dewlap is a brightly colored patch of skin on the throat, usually hidden between scales. When a display is needed, the lizards erect the hyoid bone of their throat, resulting in a large vertical flap of brightly colored skin beneath the head which can be then used for communication.
caption: Feral Jackson's Chameleon from a population introduced to Hawaii in the 1970s
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