Snakes are elongated, legless, 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 with their highly mobile jaws. 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. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. 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.Legless lizards resemble snakes, but several common groups of legless lizards have eyelids and external ears, which snakes lack, although this rule is not universal.
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, and many small islands of the Atlantic and central Pacific oceans. Additionally, sea snakes are widespread throughout the Indian and Pacific Oceans. More than 20 families are currently recognized, comprising about 520 genera and about 3,600 species. They range in size from the tiny, 10.4 cm (4.1 in)-long Barbados thread snake 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.
Of the 3,500 snake species, there are around 600 venomous snake species in the world. This is an overview of the snakes that pose a significant health risk to humans, through snakebites or other physical trauma.
The varieties of snakes that most often cause serious snakebites depend on the region of the world. In Africa, the most dangerous species include black mambas, puff adders, and carpet vipers. In the Middle East the species of greatest concern are carpet vipers and elapids; in Central and South America, Bothrops (including the terciopelo or fer-de-lance) and Crotalus (rattlesnakes) are of greatest concern. In South Asia, it has historically been believed that Indian cobras, common kraits, Russell's viper and carpet vipers were the most dangerous species; however other snakes may also cause significant problems in this area of the world. While several species of snakes may cause more bodily destruction than others, any of these venomous snakes are still very capable of causing human fatalities should a bite go untreated, regardless of their venom capabilities or behavioral tendencies.
The Most Venomous Snakes (Video)
8) Taipan – The Taipan is large, fast moving and extremely venomous. They can be found in Australia and are considered some of the most deadly known snakes. The venom in a Taipan is strong enough to kill up to 12,000 guinea pigs. When bit by this snake, the venom works quickly to paralyze the victim’s nervous system and to clot the blood, blocking the blood vessels and blood clotting. Death usually occurs within 30 minutes to an hour. They prey mostly on small mammals, especially rats.
7) Death Adder - The Death Adder are native to Australia, New Guinea and nearby islands. The fittingly named Death Adder is among the most deadly snakes in the world. They are very viper-like in their appearance and have a short body and triangular shaped heads. The Death Adder has the quickest bite in the world and can strike and return to ready position in less than .1 of a second. It releases between 40 and 100mg of venom in one bite and it may cause paralysis or death within 6 hours. Antivenom is very effective in treating a bite from a Death Adder, mainly due to the somewhat slow onset of symptoms, but before the antivenom was developed, a Death Adder bite had a fatality rate of 50%.
6) Tiger Snake – Found in the southern regions of Australia, these snakes can kill its prey as quickly as 30 minutes or as long as 24 hours after a single bite. Once bitten by the Tiger snake, some symptoms include pain in the foot, neck, numbness, tingling and sweating. It will also cause difficulty breathing and paralysis. The good news is that when encountered, the Tiger snake’s first impulse is to flee – it will usually only attack when cornered.
5) Vipers – The most Venomous vipers in the world are the Chain Viper and the Saw Scaled Viper. These vipers are found in China, India, Central Asia, Middle East and Southeast Asia. Vipers are some of the most aggressive snakes and have a very short fuse. They are quick tempered and are often active after rains. They are also very fast. It doesn’t take a lot to get them riled up and they will strike quickly and with little warning. They stalk at night and the vipers bite is very painful and will leave you in excruciating pain.
4) Black Mamba – The Black Mamba can be found in Africa and is one of the most feared snakes there. It is one of the longest venomous snakes, measuring between 6 and 10 feet. There have even been reports of black mambas as long as 15 feet. When threatened, it will open its inky black mouth, spreads its narrow neck-flap and can sometimes hiss. It delivers its bites in rapid succession and is severely venomous. Depending on the nature of the bite, death can result at any time between 15 minutes and 3 hours.
3) Inland Taipan – This snake differs from the plain old Taipan snake in that it is the deadliest land snake in existence. It could kill 100 humans with its venom which is 50 times more potent than that of a Cobra. Although it is observed to be a rather shy reptile, when it does bite it has been known to strike up to 7 times. Its bite can kill a human in 45 minutes, although no fatalities have ever been recorded due to the rarity and non-aggressive nature of this snake.
2) Blue Krait – The Blue Krait is the deadliest snake in its species. Death rate of those bitten are 50%, even if antivenom is administered. Their venom is 16 times more potent than that of a Cobra. They are nocturnal and become more aggressive in dark situations. They differ from aggressive snakes in that they would rather hide than attack. When it does bite will cause paralysis with symptoms of cramps, spasms and tremors. It usually takes its prey between 6 and 12 hours before death after a bite.
1) Belcher’s Sea Snake – We saved the most deadly for last. The Belcher Sea Snake can be found in Northern Australian and Southeast Asian waters and has the most Venomous venom known to mankind. 1000 humans can be killed with one single bite. The Belcher Sea Snake is a pretty calm snake and it’s mostly the fisherman who pull up fishing nets from the sea who get bit most often. The snake rarely goes on land and actually breathes air but can hold its breath for 7 to 8 hours while hunting and sleeping underwater. Only 25 % of those bitten are envenomed, but if the venom were used its prey would die within 30 minutes.