Scorpion

Scorpions
Hottentotta tamulus (Indian red scorpion) from Maharashtra, India
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Scorpiones
Scorpion range map

Scorpions are eight legged venomous arachnids of the order Scorpiones. They have a long body with an extended tail with a sting. The average adult scorpion is about 9 centimetres (3.5 in) in length. The longest scorpion is the Gigantometrus swammerdami (Giant forest scorpion) from India, which can be 23 centimetres (9.1 in) long.^[1] There are about 1,750 species of scorpions worldwide.^[2]

The evolutionary history of scorpions goes back to the Silurian, 430 million years ago. They have adapted to a wide range of environments, and live on all continents except Antarctica. There are 13 living families. Only about 25 species have venom which can kill a human being.^[3][4]

1. ↑ Ruppert, Edward E. 2004. et al 2004. Invertebrate zoology. Brooks/Cole. ISBN 978-81-315-0104-7
2. ↑ František Kovařík (2009). "Illustrated catalog of scorpions, Part I" (PDF). Retrieved January 22, 2011.
3. ↑ ThinkQuest: Poisonous Animals: Scorpions. 2000
4. ↑ Polis, Gary A. 1990. The biology of scorpions. Stanford University Press. ISBN 978-0-8047-1249-1 [1]