Squamata is the largest order of reptiles, including snakes, lizards, and worm-lizards, with over 7,900 species. They are characterized by scaly skin, square bones, and the ability to swallow large prey. Squamates are ectothermic and sunbathe to regulate body temperature. The order includes venomous species and the least known are the pink, burrowing worm-lizards.
Squamata is an order of reptiles that includes snakes, lizards, and amphisbaenidae (“worm-lizards”). It is the largest recent order of reptiles, with over 7,900 species. Scales account for about 96% of living reptile species. The other three living orders alongside Squamata include Crocodilia (crocodiles, gharials, caimans, and alligators), Sphenodontia (just two species of tuatara), and Testudines (turtles and tortoises). The squamates are the order of reptiles of the most varied size, ranging from the 16 mm (0.63 in) Jaragua Sphaero (a gecko), which can stand on a quarter, to the 8 m (26 ft) Green Anaconda, which it has occasionally consumed humans.
Squamata means “scaly reptile”, which is the distinguishing feature of the order: horny scales or scutes. Other orders of reptiles have scales, but they differ in shape and form from scaly scales. The scales are also known as osteoderms. Another distinguishing feature is the square bones, which allow the upper jaw to move independently of the braincase, allowing for the swallowing of very large prey items. This may allow a squamate such as a python to consume an entire deer in one gulp, although the entire gulp could take several hours.
The best known members of Squamata are snakes and lizards, with the latter constituting a paraphyletic group (consisting of more than one unrelated category). Lizards are sometimes divided into two suborders: Iguania (ignorants and chameleons) and Scleroglossa (the rest), or just one, called Lacertilia. Serpents are a suborder, called Serpentes, divided into two infraorders, one of which is just blind serpents, the other makes up the rest. About 60% of Squamata are thought to form a venomous clade Toxicofera, which includes nearly all venomous squamates and some nonvenomous snakes and lizards.
Like most other reptiles (with the exception of birds, which are descended from dinosaurs), squamates are “cold-blooded,” or more accurately, ectothermic, meaning that most of their body heat comes from outside. As a result, some squamates sunbathe on rocks to maintain body heat. Even snakes that consume very large prey items bathe in the sun to aid digestion.
The least familiar group of squamates are the pink, scaly burrowing worm-lizards that are only 6 inches long. In addition to being underground, they are very rare, mainly found in South America and Africa. Superficially, they resemble earthworms.
Protect your devices with Threat Protection by NordVPN
