| Lizards Fossil range: 199–0 Ma Jurassic- Present |
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| Central bearded dragon, Pogona vitticeps | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Superclass: | Tetrapoda |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Lacertilia* Günther, 1867 |
| Families | |
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Many, see text. |
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Lizards are a very large and widespread group of squamate reptiles, with nearly 3800 species,[1] 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. 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 trait 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 centimeters for some chameleons and geckos to nearly three meters (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 meters, and the giant monitor Megalania prisca is estimated to have reached perhaps seven meters.
Contents |
Sight is quite 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.
A 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.
The retention of the basic 'reptilian' amniote body form by lizards makes it tempting to assume any similar animal, alive or extinct, is also a lizard. However, this is not the case, and lizards as squamates are part of a well-defined group.
The earliest "lizard" was superficially lizard-like, but had a solid, box-like skull, with openings only for eyes, nostrils, etc (termed Anapsid). Turtles retain this skull form. Early anapsids later gave rise to two new groups with additional holes in the skull to make room for and anchor larger jaw muscles. Those with a single hole, the Synapsids, gave rise to the superficially lizard-like Pelycosaurs which include Dimetrodon and the Therapsids, including the Cynodonts, from which would evolve the modern mammals.
The Diapsids, possessing one temporal fenestra before the eye and one behind it, continued to diversify. One branch, the Archosaurs, retained the basic Diapsid skull, and gave rise to a bewildering array of animals, most famous being the crocodilians, the pterosaurs, the dinosaurs and their descendants, birds. The Ichthyosaurs and Plesiosaurs radiated from the same basal Diapsid group.
The smaller Lepidosaurs which would give rise to the lizards began to reduce the skull bones, making the skull lighter and more flexible. The modern Tuatara retains the basic Lepidosaur skull, distinguishing it from true lizards in spite of superficial similarities. Squamates, including snakes and all true lizards, further lightened the skull by eliminating the lower margin of the lower skull opening.
Within the Lacertilia are found four generally recognized suborders, Iguania, Gekkota, Amphisbaenia and Autarchoglossa, with the "blind skinks" in the family Dibamidae having an uncertain position. While traditionally excluded from the lizards, the snakes are usually classified as a clade with a similar subordinal rank.[2]
The suborder Iguania, found in Africa, south Asia, Australia, the New World, and with iguanas colonizing the islands of the west Pacific, form the sister group to the remainder of the squamata. They are largely arboreal, and have primitively fleshy, non-prehensile tongues, but this condition is obviously highly modified in the chameleons. This clade includes the following families:
Active hunters, the Gekkota includes three families comprising the distinctive cosmopolitan geckos and the legless flap-footed lizards of Australia and New Zealand. Like snakes, the geckos and the flap-footed lizards lack eyelids. Unlike snakes, they use their tongues to clean their often highly developed eyes. While gecko feet have unique surfaces which allow them to cling to glass and run on ceilings, the flapfoot has lost its limbs. The three families of this suborder are:
Most lizard species are harmless to humans. Only the very largest lizard species pose threat of death; the Komodo dragon, for example, has been known to stalk, attack, and kill humans[citation needed]. 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.[3] 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.[4]
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.[5]
Suborder Lacertilia (Sauria) - (Lizards)
The Lizard [1] is a peninsula in Britain and part of Cornwall in the South West. The name maybe derived from the cornish expression Lys Ardh, which means High Court. The Lizard contains Britain's most southerly point : The Lizard Point.
British Airways and Ryanair operate flights to Newquay. National Express buses go to Truro, Camborne, Falmouth and Redruth.
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Only in Lev 11:30, as rendering of Hebrew letaah, so called from its "hiding." Supposed to be the Lacerta gecko or fan-foot lizard, from the toes of which poison exudes. (See CHAMELEON.)
what mentions this? (please help by turning references to this page into wiki links)
| Lizard Fossil range: Jurassic - Recent | |||||||||||||
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| File:Haeckel | |||||||||||||
| "Lacertilia", from Ernst Haeckel's Kunstformen der Natur, 1904 | |||||||||||||
| Scientific classification | |||||||||||||
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A lizard is a kind of reptile. They are the Suborder Lacertilia, also called Sauria. Alternatively, they and the snakes are the Order Squamata.
There are about 3,800 species,[1] which live all over the world, except in cold climates. One type, the marine iguana, lives in the sea. Size varies greatly, ranging from 5 inches to the Komodo dragon's 9 feet and 150 pounds.
Some kinds of lizard are:
Contents |
Suborder Lacertilia (Sauria)
In the traditional taxonomy the Order Squamata is divided as follows:
A modern view is that the snakes and lizards are all infraorders of the Squamata: [2]p238
There are other versions, and the taxonomy will probably not settle until more molecular evidence is collected.
The skull structure of both snakes and lizards is distinctive. They can move their upper jaw relative to the braincase. They bear horny scales, and many use venom for attack and deefence.
The Squamates are definitely a monophyletic group; they are a sister group to the Tuatara. Judged by their fossil record, the Squamates were present in the Mesozoic, but occupied a minor place in the land ecology. Three of the six lines are recorded first in the Upper Jurassic, the others in the Cretaceous. Probably all (including snakes) arose earlier in the Jurassic.[2] The Mosasaurs of the Upper Cretaceous were by far the most successful of all the lizards, becoming the top predator in their ecosystem.
from a population introduced to Hawaii in the 1970s]]
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.
Coachella Valley Fringe-toed
Coachella Valley Fringe-toed Lizard, Uma inornata |
Plumed.basilisk.
Plumed Basilisk, Basiliscus plumifrons |
Gila.monster.
Gila monster, Heloderma s. suspectum |
Green.tree.monitor.lizard.
Green tree monitor lizard, Varanus prasinus |
   | Tiny gecko - BBC News | SCI/TECH | Tiny gecko is 'world's smallest' |
 | Lizards and Lizard Information - Lizards and Lizard Care |
| | Lizards at Popular Pets - Lizards - Information about Lizards |
| | Lizards' poisonous secret is revealed - Lizards' poisonous secret is revealed - life - 16 November 2005 - New Scientist |
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