The other term, serpent, is from French, ultimately from Indo-European * serp- 'to creep', which also gave Ancient Greek бј•ПЃПЂП‰ ( hГ©rpЕЌ) 'I crawl'.Д®volution A phylogenetic overview of modern snakes. The word ousted adder, as adder went on to narrow in meaning, though in Old English nГ¦ddre was the general word for snake. Germanic Schnake 'ring snake', Swedish snok 'grass snake'), from Proto-Indo-European root * (s)nД“g-o- 'to crawl to creep', which also gave sneak as well as Sanskrit nДЃgГЎ 'snake'. The English word snake comes from Old English snaca, itself from Proto-Germanic * snak-an- ( cf.

Nonvenomous snakes either swallow prey alive or kill by constriction. Some possess venom that is potent enough to cause painful injury or death to humans. Most species of snake are nonvenomous and those that have venom use it primarily to kill and subdue prey rather than for self-defense. The oldest preserved descriptions of snakes can be found in the Brooklyn Papyrus. The diversity of modern snakes appeared during the Paleocene epoch ( c.В 66 to 56В Ma ago, after the CretaceousвЂ“Paleogene extinction event). 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 fossil species Titanoboa cerrejonensis was 12.8 meters (42В ft) long. They range in size from the tiny, 10.4В cm-long (4.1В in) Barbados threadsnake to the reticulated python of 6.95 meters (22.8В ft) in length. More than twenty families are currently recognized, comprising about 520 genera and about 3,900 species. Additionally, sea snakes are widespread throughout the Indian and Pacific oceans. 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, the Hawaiian archipelago, and the islands of New Zealand, as well as many small islands of the Atlantic and central Pacific oceans. 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). Lizards have evolved elongate bodies without limbs or with greatly reduced limbs about twenty-five times independently via convergent evolution, leading to many lineages of legless lizards. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. 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 have only one functional lung. Many species of snakes have skulls with several more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads with their highly mobile jaws. Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes / s ЙњЛђr Л€ p Й› n t iЛђ z/. Approximate world distribution of snakes, all species

Green screen snake coil