Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes. Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads. To accommodate their narrow bodies, snakes' paired organs appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. Lizards have independently evolved elongate bodies without limbs or with greatly reduced limbs at least twenty-five times via convergent evolution, leading to many lineages of legless lizards. These resemble snakes, but several common groups of legless lizards have eyelids and external ears, which snakes lack, although this rule is not universal.
Amphisbaenia is a group of typically legless lizards, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As many species have a pink body and scales arranged in rings, they have a superficial resemblance to earthworms. While the genus Bipes retains forelimbs, all other genera are limbless. Phylogenetic studies suggest that they are nested within Lacertoidea, closely related to the lizard family Lacertidae. Amphisbaenians are widely distributed, occurring in North America, Europe, Africa, South America, Western Asia and the Caribbean. Most species are less than 6 inches (15 cm) long.
Pygopodidae, commonly known as snake-lizards, or flap-footed lizards, are a family of legless lizards with reduced or absent limbs, and are a type of gecko. At least 35 species are placed in two subfamilies and eight genera. They have unusually long, slender bodies, giving them a strong resemblance to snakes. Like snakes and most geckos, they have no eyelids, but unlike snakes, they have external ear holes and flat, unforked tongues. They are native to Australia and New Guinea.
Dibamidae or blind skinks is a family of lizards characterized by their elongated cylindrical body and an apparent lack of limbs. Female dibamids are entirely limbless and the males retain small flap-like hind limbs, which they use to grip their partner during mating. They have a rigidly fused skull, lack pterygoid teeth and external ears. Their eyes are greatly reduced, and covered with a scale.
Lialis is a genus of legless lizards in the family Pygopodidae. The genus is native to Australia and New Guinea.
Many vertebrates are limbless, limb-reduced, or apodous, with a body plan consisting of a head and vertebral column, but no adjoining limbs such as legs or fins. Jawless fish are limbless but may have preceded the evolution of vertebrate limbs, whereas numerous reptile and amphibian lineages – and some eels and eel-like fish – independently lost their limbs. Larval amphibians, tadpoles, are also often limbless. No mammals or birds are limbless, but some feature partial limb-loss or limb reduction.
The Brigalow scaly-foot, also known as the Queensland snake-lizard, is a species of legless lizard in the family Pygopodidae. It is endemic to Australia and is the only species in the monotypic genus Paradelma.
Burton's legless lizard is a species of lizard in the family Pygopodidae. The species lacks forelegs and has only rudimentary hind legs. Pygopodid lizards are also referred to as "legless lizards", "flap-footed lizards" and "snake-lizards". This species is native to Australia and Papua New Guinea.
The common scaly-foot is a widespread species of legless lizard in the Pygopodidae family. It is endemic to Australia.
The Carphodactylidae, informally known as the southern padless geckos, are a family of geckos, lizards in the infraorder Gekkota. The family consists of 32 described species in 7 genera, all of which are endemic to Australia. They belong to the superfamily Pygopodoidea, an ancient group of east Gondwanan geckos now only found in Australasia. Despite their well-developed limbs, molecular phylogenies have demonstrated that Carphodactylidae is the sister group to Pygopodidae, a highly specialized family of legless lizards.
The hooded scaly-foot, also known as western scaly-foot, black-headed scaly-foot or western hooded scaly-foot, is an endemic Australian legless lizard of the family Pygopodidae.
The pink-tailed worm-lizard or granite worm-lizard is a rare legless lizard found in Australia. The animal looks like a combination of small snake and worm. Its total length is up to 14 cm. It has a pink tail and is white underneath. The head and neck are brown, and the rest of the top of the body is pale grey. Scales on the back each have a dark bar, giving the appearance of dots down the back. It is found on two hills near Tarcutta, Bathurst, New South Wales, Bendigo in Victoria, and along the sides of the Molonglo River and Murrumbidgee River and on Mount Taylor in the Australian Capital Territory. The lizards eat invertebrates that live under rocks. They can be found under rocks sized from 0.15 to 0.6 m. Their main diet is ant eggs, particularly from Iridomyrmex species and Rhytidoponera metallica.
The eastern hooded scaly-foot or eastern scaly-foot is a species of flap-footed lizard found in the complex heaths of the lower west coast and the spinifex grasslands of mainland Australia. They are popular pets and are often mistaken for snakes due to their limbless appearance.
The Papua snake lizard, also known commonly as Jicar's snake-lizard, the New Guinea snake-lizard, and the Papua snake-lizard, is a species of legless lizard in the family Pygopodidae. The species is endemic to New Guinea including the Bismarck Archipelago.
Pygopodoidea is a gecko superfamily and the only taxon in the gekkotan subclade Pygopodomorpha. The clade includes three Australasian families: Diplodactylidae, Carphodactylidae, and Pygopodidae. Traditional gekkotan systematics had considered Diplodactylidae and Carphodactylidae as subfamilies of the family Gekkonidae, but recent molecular work have placed Pygopodidae within Gekkonidae making it paraphyletic. These analyses have shown support of Pygopodidae and Carphodactylidae being sister taxa, with Diplodactylidae occupying a basal position in Pygopodoidea.
Delma butleri, also known commonly as Butler's legless lizard, Butler's scalyfoot, the spinifex snake-lizard, and the unbanded delma, is a species of lizard in the family Pygopodidae. The species is endemic to Australia.
The excitable delma is a species of lizard in the Pygopodidae family endemic to Australia. The lizard gets its name from its active and jumpy defense mechanism. It will erratically jump multiple times in succession, each jump pivoting its body in a different direction. D. tincta is a slender, long legless lizard that through evolution lost its limbs. It is found throughout Australia in a variety of habitats, and spends most of its time hiding. Due to its nocturnal nature, it is rare to spot in the wild. This legless lizard is small to moderate in size, with a tail that is three to four times its body length. The typical size of the excitable delma is 250 – 300 mm. This lizard is an insectivore and feeds on insects it finds when travelling through grass, logs, surface soil, and loose rocks. Like all pygopodids, the excitable delma is oviparous and only lays two eggs per clutch.
The Mallee worm-lizard , also known as the pink-nosed worm-lizard and the red-tailed worm-lizard, is a slender pygopid species that is endemic to Australia, with recorded distribution across the four southern mainland states, although its distribution is restricted in Western Australia and New South Wales.
The striated worm-lizard is a species of legless lizard in the family Pygopodidae. It is endemic to southern Australia. Commonly known as Striated worm-lizard but has also been referred to as the Striped or Lined worm-lizard due to its pattern of long, thin parallel streaks. Some populations such as those in WA and Kangaroo Island may have absent stripes or the lines present as lines of dots.
The olive legless lizard is a species of legless gecko from the Pygopodidae family. This species is commonly found throughout the Australian Capital Territory, New South Wales, Queensland and southeastern South Australia, mostly inhabiting areas consisting of dry to temperate southern grasslands and grassy woodlands.
