Squamata

From New World Encyclopedia
Revision as of 01:45, 1 December 2007 by Rick Swarts (talk | contribs)
Scaled reptiles
Brown tree snake and Green anole
Brown tree snake and Green anole
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Order: Squamata
Oppel, 1811
black: range of Squamata
black: range of Squamata
Suborders

see text

This article is about the Squamata order of reptiles. For the Roman scale armour see: Lorica squamata.

Squamata (scaled reptiles) is the largest recent order of reptiles, including lizards and snakes. Members of the order are distinguished by their skins, which bear horny scales or shields. They also possess movable quadrate bones, making it possible to move the upper jaw relative to the braincase. This is particularly visible in snakes, which are able to open their mouths very widely to accommodate comparatively large prey. The male members of the group Squamata are the only vertebrates with a hemipenis. This is also the only reptile group in which can be found both viviparous and ovoviviparous species, as well as the usual oviparous reptiles.

Overview

Add info on reptiles here

Groups

Classically, the order is divided into three suborders:

Of these, the lizards form a paraphyletic group. In newer classifications the name Sauria is used for reptiles and birds in general, and the Squamata are divided differently:

  • Suborder Iguania (the iguanas and chameleons)
  • Suborder Scleroglossa
    • Infraorder Gekkota (the geckos)
    • Infraorder Anguimorpha (the monitors, goannas, Komodo dragon, Gila monster, and slow-worms)
    • Infraorder Scincomorpha (skinks, whiptail lizards and common European lizards)
    • Infraorder Serpentes (the snakes)
    • Infraorder Amphisbaenia

The exact relationships within these two suborders are not entirely certain yet, though recent research strongly suggests that several families form a venom clade which encompasses a majority (nearly 60%) of Squamate species.

The Squamata do not include the tuataras, New Zealand reptiles resembling lizards.

References
ISBN links support NWE through referral fees

External links

{[credit|Squamata|172960739}}