Lizards

For other uses, see Lizard (disambiguation).

Lizard Fossil range: Jurassic - Recent
"Lacertilia", from Ernst Haeckel\'s Artforms of Nature, 1904
Scientific classification
Kingdom: Animalia Phylum: Chordata Superclass: Tetrapoda Class: Sauropsida Order: Squamata Suborder: Lacertilia* Günther, 1867
Families
Many, see text.

Lizards are reptiles of the order Squamata, normally possessing four legs and external ear openings. The adult length of species within the order range from a few centimeters (some Caribbean geckos) to nearly three meters (Komodo Dragons).

Contents 1 Description 2 Relationship to humans 3 Classification 4 References 5 Cited references

Description

Lizards are reptiles, often four-legged, with an integumentary system comprising scales, with a skull composed of quadrate bones. Lizards possess external ears and most have movable eyelids. Encompassing forty families, there is tremendous variety in colour, appearance and size. Due to their smooth, shiny appearance, some lizards can appear slimy or slippery although their skin is actually very dry due to a lack of pores to excrete water and oils.

Lizards have scales on their skin which may be tubercular or have ossified encrustations called osteoderms.Smith, Malcolm A. (1943), The Fauna of British India, Ceylon and Burma Vol II - Sauria, pg 2 & 3.

Most lizards are oviparous, though a few species are viviparous. Many are also capable of regeneration of lost limbs or tails.

Some lizard species, including the glass lizard and legless lizards, have some vestigial structures though no functional legs. They are distinguished from true snakes by the presence of eyelids and ears and a tail that can sometimes break off as a physical defence mechanism. Many lizards are good climbers or fast sprinters. Some can run bipedally, such as the collared lizard and the world\'s fastest lizard, the spiny-tailed iguana of the genus Ctenosaura.

Many lizards can change colour in response to their environments or in times of stress. The most familiar example is the chameleon, but more subtle colour changes occur in other lizard species as well such as the anole, also known as the "American chameleon," "house chameleon" or "chamele".

Lizards in the Scincomorpha family, which include skinks (such as the blue-tailed skink), often have shiny, iridescent scales that appear moist. They are dry-skinned and generally prefer to avoid water. All lizards are capable of swimming if needed and a few (such as the Nile monitor) are quite comfortable in aquatic environments.

Relationship to humans

Moche Ceramic Depicting Lizard. 200 A.D. Larco Museum Collection Lima, Peru.

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. The venom of the Gila monster and beaded lizard is not usually deadly but they can inflict extremely painful bites due to powerful jaws. The chief impact of lizards on humans is positive as they are significant predators of pest species; numerous species are prominent in the pet trade; some are eaten as food (for example, Green Iguanas in Central America); and lizard symbology plays important, though rarely predominant roles in some cultures (e.g. Tarrotarro in Australian mythology). The Moche people of ancient Peru worshipped animals and often depicted lizards in their art.Berrin, Katherine & Larco Museum. The Spirit of Ancient Peru:Treasures from the Museo Arqueológico Rafael Larco Herrera. New York: Thames and Hudson, 1997.

Classification

Plumed Basilisk, Basiliscus plumifrons

Zebra-tailed Lizard, Callisaurus draconoides

Red-headed rock agama, Agama agama

Gila monster, Heloderma s. suspectum

Green tree monitor lizard, Varanus prasinus

Two Tegus, Tupinambis merianae

Suborder Lacertilia (Sauria) - (Lizards)

• Family Bavarisauridae
• Family Eichstaettisauridae
• Infraorder Iguania
  • Family Arretosauridae
  • Family Euposauridae
  • Family Corytophanidae (casquehead lizards)
  • Family Iguanidae (iguanas and spinytail iguanas)
  • Family Phrynosomatidae (earless, spiny, tree, side-blotched and horned lizards)
  • Family Polychrotidae (anoles)
    • Family Leiosauridae (see Polychrotinae)
  • Family Tropiduridae (neotropical ground lizards)
    • Family Liolaemidae (see Tropidurinae)
    • Family Leiocephalidae (see Tropidurinae)
  • Family Crotaphytidae (collared and leopard lizards)
  • Family Opluridae (Madagascar iguanids)
  • Family Hoplocercidae (wood lizards, clubtails)
  • Family Priscagamidae
  • Family Isodontosauridae
  • Family Agamidae (agamas)
  • Family Chamaeleonidae (chameleons)
• Infraorder Gekkota
  • Family Gekkonidae (geckos)
  • Family Pygopodidae (legless lizards)
  • Family Dibamidae (blind lizards)
• Infraorder Scincomorpha
  • Family Paramacellodidae
  • Family Slavoiidae
  • Family Scincidae (skinks)
  • Family Cordylidae (spinytail lizards)
  • Family Gerrhosauridae (plated lizards)
  • Family Xantusiidae (night lizards)
  • Family Lacertidae (wall lizards or true lizards)
  • Family Mongolochamopidae
  • Family Adamisauridae
  • Family Teiidae (tegus and whiptails)
  • Family Gymnophthalmidae (spectacled lizards)
• Infraorder Diploglossa
  • Family Anguidae (glass lizards)
  • Family Anniellidae (American legless lizards)
  • Family Xenosauridae (knob-scaled lizards)
• Infraorder Platynota (Varanoidea)
  • Family Varanidae (monitor lizards)
  • Family Lanthanotidae (earless monitor lizards)
  • Family Helodermatidae (gila monsters Chinese water dragon & beaded lizards)
  • Family Mosasauridae (marine lizards)

References

• Bebler, John L. (1979). The Audubon Society Field Guide to Reptiles and Amphibians of North America. Alfred A. Knopf, 581. ISBN 0394508246. 
• Capula, Massimo; Behler (1989). Simon & Schuster\'s Guide to Reptiles and Amphibians of the World. New York: Simon & Schuster. ISBN 0671690981. 
• Cogger, Harold (1992). Reptiles & Amphibians. Sydney, Australia: Weldon Owen. ISBN 0831727861. 
• Conant, Roger (1991). A Field Guide to Reptiles and Amphibians Eastern/Central North America. Boston, Massachusetts: Houghton Mifflin Company. ISBN 0395583896. 
• Ditmars, Raymond L (1933). Reptiles of the World: The Crocodilians, Lizards, Snakes, Turtles and Tortoises of the Eastern and Western Hemispheres. New York: Macmillian, 321. 
• Freiberg, Dr. Marcos (1984). The World of Venomous Animals. New Jersey: TFH Publications. ISBN 0876665679. 
• Gibbons, J. Whitfield (1983). Their Blood Runs Cold: Adventures With Reptiles and Amphibians. Alabama: University of Alabama Press, 164. ISBN 978-0817301354. 
• Rosenfeld, Arthur (1989). Exotic Pets. New York: Simon & Schuster, 293. ISBN 067147654. 

Cited references

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