The tail and sting of a South African burrowing scorpion (Scorpionidae: Opistophthalmus sp.) © Jan A. Neethling 2012
Scorpions have been around for more than 420 million years. Originally aquatic, they were some of the first creatures to venture onto land and have since taken up a completely terrestrial lifestyle. They occur on every continent except Antarctica, and are most prevalent in arid regions, though many species do occur in the tropics. They are amongst the most recognizable arachnids and are characterized by an elongate body, pincer-like grasping appendages (called pedipalps), four pairs of walking legs and a tail that terminates in a sting (telson).