Squamates are one of the four basic groups of reptiles and include an amazing diversity of animals—nearly 8,000 living species. Squamates are divided into three groups—the lizards, snakes and worm lizards. Here, we'll explore some basic facts about squamates to better understand the members of this group and what makes them different from other reptiles.
FACT: Squamates are divided into 3 groups.
The three groups of squamates are lizards, snakes and worm lizards (also known as amphisbaneans). Lizards include iguanas, chisel-teeth lizards, chameleons, night lizards, skings, blind lizards, geckos, anguids, beaded lizards and many others. Snakes include blindsnakes, sunbeam snakes, boas and pythons, filesnakes, stilleto snakes, vipers and pit vipers, cobras and colubrids. Worm lizards include an assortment of species grouped by the climate region they inhabit (there tropical worm lizards, North American worm lizards and Palearctic worm lizards) as well as a group from Mexico called the Ajolotes.
FACT: There are between 7,400 and 8,000 species of squamates alive today (depending on how you classify them).
Although estimates vary widely, there are approximately 8,000 species of squamates alive today (though there are some estimates of squamate species diversity that are lower and others that are higher). Of the three squamate groups, the lizards are the most diverse (with about 4,500 species) followed by the snakes (about 2,900 species) and the worm lizards (about 130 species).
FACT: The smallest living squamate is the Virgin Islands Dwarf Sphaerodactylus.
The Virgin Islands dwarf sphaerodactylus is the smallest living squamate and is also one of the smallest living terrestrial vertebrates. It measures less than three-quarters of an inch and weighs a little over one-tenth of a gram. The Virgin Islands dwarf sphaerodactylus lives on the British Virgin Islands of Virgin Gorda, Mosquito, and Tortola. This tiny squamate is classified in the gecko family.
FACT: The largest living squamate is the Komodo dragon.The Komodo dragon is the largest living squamate, weighing over 350 pounds and growing to more than 10 feet in length. Komodo dragons are a species of monitor lizard found on the Indonesionan islands of Komodo, Flores, Padar, Rinca and Gili Montag.
FACT: Some squamates have four legs, while others have two legs or no legs at all.
The squamates are varied in the number and structure of their limbs. Many lizards have four legs but some, such as the limbless lizards (also known as the flap-footed lizards) have no legs at all. Most worm lizards are leggless with the exception of the bipedidae, which have two small forelimbs. Snakes, like the limbless lizards, have no legs.
FACT: The common leaf-tail gecko has more than 300 teeth.
The common leaf-tailed gecko (Uroplatus fimbriatus) has a ludicrous number of teeth in its mouth—according to Darren Naish of Tetrapod Zoology there are 169 teeth in its upper jaw and 148 in its lower jaw. It has so many teeth it has the distinction of being the toothiest land animal alive today.
FACT: Some squamates can glide through the air.
The best known of these airborne squamates are the draco lizards, also known more commonly as the flying dragons. Flying dragons are able to glide thanks to ribs that are covered with a membrane that, when expanded, forms a wing-like surface. This enables them to glide distances of several dozen meters (flying dragons can only glide, they cannot fly under their own power like birds). Another squamate that has taken to the air is the paradise tree snake, which flattens its body to form a flight-worthy shape and thus enable it to glide through the air.