Scorpions are predatory arthropod animals of the order
Scorpiones within the class Arachnida. They have eight legs and are easily recognised by the pair of grasping claws and the narrow, segmented tail, carried in a characteristic forward curve over the back, ending with a venomous stinger. Though the scorpion has a fearsome reputation as venomous, only 25 species have venom capable of killing a human being. While a variety of physiological, morphological, biochemical and ecological adaptations have allowed the scorpions to flourish on earth from the Silurian period (
443 to 416 million years ago) onwards, the basic shape of the scorpion has not changed significantly
Scorpions are found widely distributed over all continents, except Antarctica, in a variety of terrestrial habitats except the high latitude tundra. They have been introduced by humans to England and New Zealand. Scorpions number about 1752 described species with thirteen extant families recognised to date. The taxonomy has undergone changes and is likely to change further, as a number of genetic studies are bringing forth new information.
