Description

Snakes are elongated, legless, carnivorous reptiles of the suborderSerpentes that can be distinguished from legless lizards by theirlack of eyelids and external ears. Like all squamates, snakes areectothermic, amniote vertebrates covered in overlappingscales. Manyspecies of snakes have skulls with several more joints than theirlizard ancestors, enabling them to swallow prey much larger thantheir heads with their highly mobile jaws. To accommodate theirnarrow bodies, snakes' paired organs (such as kidneys) appear onein front of the other instead of side by side, and most have onlyone functional lung. Some species retain a pelvic girdlewith a pairof vestigial claws on either side of the cloaca. Living snakes arefound on every continent except Antarctica, and on most smallerland masses — exceptions include some large islands, such asIreland and New Zealand, and many small islands of the Atlantic andcentral Pacific. Additionally, sea snakes are widespread throughoutthe Indian and Pacific Oceans. More than 20 families are currentlyrecognized, comprising about 500 generaand about 3,400 species.They range in size from the tiny, 10 cm-long thread snake to thereticulated python of up to 6.95 meters (22.8 ft) in length. Thefossil species Titanoboa cerrejonensis was 13 meters (43 ft) long.Snakes are thought to have evolved from either burrowing or aquaticlizards, perhaps during the Jurassic period, with the earliestknown fossils dating to between 143 and 167 Ma ago. The diversityof modern snakes appeared during the Paleocene period. The oldestpreserved descriptions of snakes can be found in the BrooklynPapyrus. Most species are nonvenomous and those that have venom useit primarily to kill and subdue prey rather than for self-defense.Some possess venom potent enough to cause painful injury or deathto humans. Nonvenomous snakes either swallow prey alive or killbyconstriction. Get it free…for snakes wallpaper but not anaconda.Support for all Android Mobile Devices.