This page is about Lizards, the order of reptile. For alternate uses, see Lizard (disambiguation)

Lizards are reptiles of the order Squamata, which they share with the snakes. They are usually four-legged, with external ear openings and movable eyelids. Species range in adult length from a few centimeters (some Caribbean geckos) to nearly three meters (Komodo dragons).

Some lizard species called "glass snakes" or "glass lizards" have no functional legs, though there are some vestigial skeletal leg structures. They are distinguished from true snakes by the presence of eyelids and ears.

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

Lizards typically feed on insects or rodents. A few species are omnivorous and can also eat plants. Only two lizard species are venomous: the Mexican beaded lizard and the Gila monster, both of which live in northern Mexico and the southwest United States. They are typically not hazardous to humans as their poison is introduced slowly by chewing, rather than injected as with most poisonous snakes.

Other small lizards are harmless to humans (most species native to North America, for example, are incapable of drawing blood with their bites).

Most lizards lay eggs, though a few species are capable of live birth. Many are also capable of regeneration of lost limbs, such as tails.

Lizards in the Scincomorpha family, which include skinks (such as the blue-tailed skink), often have shiny, iridescent scales that appear moist. But like all other lizards, they are dry-skinned, generally preferring to avoid water (though all lizards are able to swim if needed).

Zebra tailed lizard from Death Valley

Classification

Suborder Sauria (Lacertilia) - (Lizards)

• Infraorder Iguania
  • Family Agamidae (agamas)
  • Family Chamaeleonidae (chameleons)
  • Family Corytophanidae (casquehead lizards)
  • Family Crotaphytidae (collared and leopard lizards)
  • Family Hoplocercidae (wood lizards, clubtails)
  • Family Iguanidae (iguanas and spinytail iguanas)
  • Family Leiocephalidae (see Tropidurinae)
  • Family Leiosauridae (see Polychrotinae)
  • Family Liolaemidae (see Tropidurinae)
  • Family Opluridae (Madagascar iguanids)
  • Family Phrynosomatidae (earless, spiny, tree, side-blotched and horned lizards)
  • Family Polychrotidae (anoles)
  • Family Tropiduridae (neotropical ground lizards)
• Infraorder Gekkota
  • Family Gekkonidae (geckos)
  • Family Pygopodidae (legless lizards)
  • Family Dibamidae (blind lizards)
• Infraorder Scincomorpha
  • Family Scincidae (skinks)
  • Family Lacertidae (wall lizards or true lizards)
  • Family Teiidae (tegus)
  • Family Cordylidae (spinytail lizards)
  • Family Gerrhosauridae (plated lizards)
  • Family Gymnophthalmidae (spectacled lizards)
  • Family Xantusiidae (night 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)

Plumed Basilisk (Basiliscus plumifrons) of the family Corytophanidae.

References

• Anthony Herrel's lizard page (http://www.uia.ac.be/u/aherrel/lizards/animals.html)
• The EMBL reptile database (http://www.embl-heidelberg.de/~uetz/LivingReptiles.html)
• Tiny gecko (http://news.bbc.co.uk/hi/english/sci/tech/newsid_1689000/1689313.stm) - the 'world's smallest' lizard