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The Snake Portal

Trimeresurus sabahi

Snakes are elongated limbless reptiles of the suborder Serpentes (/sɜːrˈpɛntiːz/). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have skulls with several more joints than their lizard ancestors and relatives, enabling them to swallow prey much larger than their heads (cranial kinesis). To accommodate their narrow bodies, snakes' paired organs (such as kidneys) appear one in front of the other instead of side by side, and most only have 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 (see Amphisbaenia, Dibamidae, and Pygopodidae).

Living snakes are found on every continent except Antarctica, and on most smaller land masses; exceptions include some large islands, such as Ireland, Iceland, Greenland, and the islands of New Zealand, as well as many small islands of the Atlantic and central Pacific oceans. Additionally, sea snakes are widespread throughout the Indian and Pacific oceans. Around thirty families are currently recognized, comprising about 520 genera and about more than 4,170 species. They range in size from the tiny, 10.4 cm-long (4.1 in) Barbados threadsnake to the reticulated python of 6.95 meters (22.8 ft) in length. The fossil species Titanoboa cerrejonensis was 12.8 meters (42 ft) long. Snakes are thought to have evolved from either burrowing or aquatic lizards, perhaps during the Jurassic period, with the earliest known fossils dating to between 143 and 167 Ma ago. The diversity of modern snakes appeared during the Paleocene epoch (c. 66 to 56 Ma ago, after the Cretaceous–Paleogene extinction event). The oldest preserved descriptions of snakes can be found in the Brooklyn Papyrus. (Full article...)

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Venom in snakes and some lizards is a form of saliva that has been modified into venom over its evolutionary history. In snakes, venom has evolved to kill or subdue prey, as well as to perform other diet-related functions. While snakes occasionally use their venom in self defense, this is not believed to have had a strong effect on venom evolution. The evolution of venom is thought to be responsible for the enormous expansion of snakes across the globe.

The evolutionary history of snake venom is a matter of debate. Historically, snake venom was believed to have evolved once, at the base of the Caenophidia, or derived snakes. Molecular studies published beginning in 2006 suggested that venom originated just once among a putative clade of reptiles, called Toxicofera, approximately 170 million years ago. Under this hypothesis, the original toxicoferan venom was a very simple set of proteins that were assembled in a pair of glands. Subsequently, this set of proteins diversified in the various lineages of toxicoferans, including Serpentes, Anguimorpha, and Iguania: several snake lineages also lost the ability to produce venom. The Toxicoferan hypothesis was challenged by studies in the mid-2010s, including a 2015 study which found that venom proteins had homologs in many other tissues in the Burmese python. The study therefore suggested that venom had evolved independently in different reptile lineages, including once in the Caenophid snakes. Venom containing most extant toxin families is believed to have been present in the last common ancestor of the Caenophidia: these toxins subsequently underwent tremendous diversification, accompanied by changes in the morphology of venom glands and delivery systems. (Full article...)

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... that Kenji Tanigaki, the action director of Rurouni Kenshin and Snake Eyes: G.I. Joe Origins, began his career as a stuntman on the invitation of action choreographer Stephen Tung?
... that table tennis commentator Adam Bobrow's nickname "Snakeman" comes from a trick shot called "the snake"?
... that Vanita Jagdeo Borade has been called the "Snake Woman" for having rescued more than 50,000 snakes?
... that the Japanese fire-bellied newt tends to show its belly to birds but wag its tail at snakes?
... that Olivia Rodrigo can write ballads about homeschooled girls as well as about songbirds and snakes?
... that the Voice of Freedom had to counter venomous snakes, leeches, and other wildlife?

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... that the Honduran milk snake's color resemblance to the coral snake, known as Batesian mimicry, helps protect it from potential predators?
...that the range of Nelson's Milksnake (Albino specimen pictured) from Mexico is linked to watercourses, and that it was thought to be the same subspecies as the more common Sinaloan Milksnake until 1978?
... that forest cobras (pictured) can grow up to 2.7 metres (8.9 feet) and kill in 20 minutes?
... that Dubois' seasnake is one of at least seventeen sea snake species living in the Coral Sea, and has the world's most toxic sea snake venom?
... that Lycodon chrysoprateros, a snake species endemic to the Philippines, is considered critically endangered because its range is only 52 square kilometres (20 sq mi)?

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Featured snake-related articles - George Went Hensley - List of snakes of Trinidad and Tobago
Good snake-related articles - Agkistrodon piscivorus - Bitis arietans - Bitis gabonica - Black mamba - Black-necked spitting cobra - Eastern green mamba - Forest cobra - Hydrophiinae - Many-banded krait - Nerodia clarkii - Russell's viper - Snake scales - Vipera berus - Western green mamba

General images

The following are images from various snake-related articles on Wikipedia.

Image 1Tetrapodophis (from Snake)
Image 2Mouse embryo 12 day post fertilization side by side with corn snake embryo 2 days post ovo-positioning. (from Snake)
Image 3Most common symptoms of any kind of snake bite envenomation. Furthermore, there is vast variation in symptoms between bites from different types of snakes. (from Snake)
Image 4The garter snake has been studied for sexual selection. (from Snake)
Image 5Eupodophis descouensi hind leg (from Snake)
Image 6Snake coiled on a stick in Oklahoma. It was brumating in a large pile of wood chips, found by this landscaper after he bulldozed the pile in late autumn 2018. (from Snake)
Image 7African egg-eating snake eating an egg (from Snake)
Image 8A line diagram from The Fauna of British India by G. A. Boulenger (1890), illustrating the terminology of shields on the head of a snake (from Snake)
Image 9A red-sided garter snake (from Narcisse Snake Dens)
Image 10Common Blind Snake (Ramphotyphlops braminus) (from List of snakes of South Asia)
Image 11The lateral view of a king cobra's skull showing fangs (from Venomous snake)
Image 12The skeletons of snakes are radically different from those of most other reptiles (as compared with the turtle here, for example), consisting almost entirely of an extended ribcage. (from Snake)
Image 13Eupodophis descouensi (from Snake)
Image 14Innocuous milk snakes are often mistaken for coral snakes whose venom is deadly to humans. (from Snake)
Image 15Golden tree snake climbing a flower (from Snake)
Image 16Australia-Oceania Köppen Map (from Australian snake habitats)
Image 17Eupodophis descouensi (from Snake)
Image 18Reticulated python skull, showing jaw movements when swallowing (from Snake)
Image 19A snaked coiled in the cavity of a tree (from Snake)
Image 20Diagram illustrating differential somite size due to difference in somitogenesis clock oscillation (from Snake)
Image 21Narcisse Snake Dens welcome sign (from Narcisse Snake Dens)
Image 22Medusa (1597) by the Italian artist Caravaggio (from Snake)
Image 23Rod of Asclepius, in which the snake, through ecdysis, symbolizes healing (from Snake)
Image 24Close up of a red-sided garter snake
Image 25Wart snake (Acrochordus granulatus) (from List of snakes of South Asia)
Image 26Approximate world distribution of snakes (from Snake)
Image 27The reverse side of the throne of Pharaoh Tutankhamun with four golden uraeus cobra figures. Gold with lapis lazuli; Valley of the Kings, Thebes (1347–37 BCE). (from Snake)
Image 28Crawling prints of a snake (from Snake)
Image 29Snakes composing a bronze kerykeion from the mythical Longanus river in Sicily (from Snake)
Image 30A neonate sidewinder rattlesnake (Crotalus cerastes) sidewinding (from Snake)
Image 31Vipera berus, one fang in glove with a small venom stain, the other still in place (from Snake)
Image 32The Binocellate Cobra(naja naja) (from List of snakes of South Asia)
Image 33Dolichophis jugularis preying on a sheltopusik (from Snake)
Image 34Common Tree Snake (from Australian snake habitats)
Image 35The world's most venomous snake, based on LD₅₀, is the inland taipan of Australia. (from Venomous snake)
Image 36An adult Barbados threadsnake, Leptotyphlops carlae, on an American quarter dollar (from Snake)
Image 37A common watersnake shedding its skin (from Snake)
Image 38Eastern hognose hooding. (from Snake)
Image 39Snake meat, in a Taipei restaurant (from Snake)
Image 40Ballcourt marker from the Postclassic site of Mixco Viejo in Guatemala. This sculpture depicts Kukulkan, jaws agape, with the head of a human warrior emerging from his maw. (from Snake)
Image 41The Indian cobra is the most common subject of snake charmings. (from Snake)