Scaled reptiles are the lizards, snakes and slowworms that make up the order known as the Squamata. They all have scaly skins, and all male squamates have two penises.
In order to see this content you need to have an up-to-date version of Flash installed and Javascript turned on.
Completely legless
Remote snake ancestors would have had legs, unlike their descendants.
Remote snake ancestors would have had legs, unlike their descendants.
The shading illustrates the diversity of this group - the darker the colour the greater the number of species. Data provided by WWF's Wildfinder.
The Squamata, or the scaled reptiles, are the largest recent order of reptiles, comprising all lizards and snakes. With over 9000 species, it is second-largest order of vertebrates after the Perciformes. 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 wide to accommodate comparatively large prey. They are the most variably sized order of reptiles, ranging from the 16 mm (0.63 in) dwarf gecko (Sphaerodactylus ariasae) to the 6.6 m (22 ft) green anaconda (Eunectes murinus) and the now-extinct mosasaurs, which reached lengths of 14 m (46 ft).
Among the other reptiles, squamates are most closely related to tuataras, which superficially resemble lizards.
This entry is from Wikipedia, the user-contributed encyclopedia. If you find the content in the 'About' section factually incorrect, defamatory or highly offensive you can edit this article at Wikipedia. For more information on our use of Wikipedia please read our FAQ.
BBC © 2013 The BBC is not responsible for the content of external sites. Read more.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.