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The Magical World of Lizards WWW.GOODNEWS.WS

7 anni fa6.4K views Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains. The group, traditionally recognized as the suborder Lacertilia, is defined as all extant members of the Lepidosauria (reptiles with overlapping scales), which are neither sphenodonts (i.e., tuatara) nor snakes -- they form an evolutionary grade. While the snakes are recognized as falling phylogenetically within the anguimorph lizards from which they evolved, the Sphenodonts are the sister group to the Squamates, the larger monophyletic group, which includes both the lizards and the snakes.Lizards typically have limbs and external ears, while snakes lack both 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 a more primitive and solid diapsid skull. Many lizards can detach their tails to escape from predators, an act called autotomy, but this ability is not shared by all lizards. 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.The adult length of species within the suborder ranges from a few cm for some chameleons and geckos to nearly three metres (9 feet, 6 inches) in the case of the largest living varanid lizard, the Komodo Dragon. Some extinct varanids reached great size. The extinct aquatic mosasaurs reached 17 metres, and the giant monitor Megalania prisca is estimated to have reached perhaps seven metres.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 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 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, 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. Anoles are particularly famous for this display, with each species having specific colors, including patterns only visible under ultraviolet (UV) light, as lizards can often see UV (Which is required for their survival, otherwise they develop metabolic. Relationship with humans; Most lizard species are harmless to humans. Only the largest lizard species, the Komodo dragon, which reaches 3.3 metres (11 feet) in length and weighs up to 166 kg (365 pounds), has been known to stalk, attack, and, on occasion, kill humans. An eight-year-old Indonesian boy died from blood loss after an attack in 2007. The venom of the Gila monster and beaded lizard is not usually deadly but they can inflict extremely painful bites due to powerful jaws.Numerous species of lizard are kept as pets.Lizard symbolism plays important though rarely predominant roles in some cultures (e.g., Tarrotarro in Australian Aboriginal mythology). The Moche people of ancient Peru worshiped animals and often depicted lizards in their art.According to a popular legend in Maharashtra, a Common Indian Monitor, with ropes attached, was used to scale the walls of the Sinhagad fort in the Battle of Sinhagad.Green Iguanas are eaten in Central America and Uromastyx in Africa. In North Africa, Uromastyx are considered dhaab or 'fish of the desert' and eaten by nomadic tribes. The Magical World of Lizards WWW.GOODNEWS.WS 

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