page_title: Scorpion
section_title: Taxonomy
hierarchical_section_title: Scorpion / Evolution / Taxonomy
caption_attribution_description: English: A Giant Forest Scorpion from the Western ghats in Karnataka, India
context_page_description: Scorpions are predatory arachnids of the order Scorpiones. They have eight legs and are easily recognized by the pair of grasping pedipalps and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger. Scorpions range in size from 9–12 mm in Microtityus minimus to 23 cm in Heterometrus swammerdami.
  The evolutionary history of scorpions goes back to the Silurian period 435 million years ago. They have adapted to a wide range of environmental conditions, and they can now be found on all continents except Antarctica. There are about 1,750 described species, with 13 extant families recognised to date. Their taxonomy is being revised in the light of genomic studies.
  The vast majority do not represent a serious threat to humans, and healthy adults usually do not need medical treatment after being stung. Only about 25 species have venom capable of killing a human. In some parts of the world with highly venomous species, human fatalities regularly occur, primarily in areas with limited access to medical treatment.
  Scorpions with their powerful sting appear in art, folklore, mythology and numerous brands.
context_section_description: Thirteen families and about 1,750 species and subspecies of scorpions have been described. In addition, 111 described taxa of scorpions are extinct. The smallest known species is the 9–12 mm (0.35–0.47 in) Microtityus minimus in the Buthidae, while the largest species is the 23 cm (9.1 in) Heterometrus swammerdami in the Scorpionidae. This classification is based on Soleglad and Fet (2003), which replaced Stockwell's older, unpublished classification. Additional taxonomic changes are from papers by Soleglad et al. (2005).
  The extant taxa to the rank of family (numbers of species in parentheses) are:
  Order Scorpiones
  Parvorder Pseudochactida Soleglad et Fet, 2003
  Superfamily Pseudochactoidea Gromov, 1998
  Family Pseudochactidae Gromov, 1998 (1 sp)
  Parvorder Buthida Soleglad et Fet, 2003
  Superfamily Buthoidea C. L. Koch, 1837
  Family Buthidae C. L. Koch, 1837 (thick-tailed scorpions) (1209 spp)
  Family Microcharmidae Lourenço, 1996, 2019 (17 spp)
  Parvorder Chaerilida Soleglad et Fet, 2003
  Superfamily Chaeriloidea Pocock, 1893
  Family Chaerilidae Pocock, 1893 (51 spp)
  Parvorder Iurida Soleglad et Fet, 2003
  Superfamily Chactoidea Pocock, 1893
  Family Chactidae Pocock, 1893 (209 spp)
  Family Euscorpiidae Laurie, 1896 (170 spp)
  Family Superstitioniidae Stahnke, 1940 (1 sp)
  Family Vaejovidae Thorell, 1876 (222 spp)
  Superfamily Iuroidea Thorell, 1876
  Family Caraboctonidae Kraepelin, 1905 (hairy scorpions) (23 spp)
  Family Iuridae Thorell, 1876 (14 spp)
  Superfamily Scorpionoidea Latreille, 1802
  Family Bothriuridae Simon, 1880 (158 spp)
  Family Hemiscorpiidae Pocock, 1893 (=Ischnuridae, =Liochelidae) (rock, creeping, or tree scorpions) (16 spp)
  Family Scorpionidae Latreille, 1802 (burrowing or pale-legged scorpions) (183 spp)
caption: Heterometrus swammerdami, the largest living species
exif: {"Image ImageDescription": "", "Image Make": "NIKON", "Image Model": "COOLPIX S3300", "Image Orientation": "Horizontal (normal)", "Image Software": "COOLPIX S3300V1.0", "Image DateTime": "2014:06:13 20:50:35", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "2252", "Image Padding": "[]", "EXIF ExposureTime": "1/25", "EXIF FNumber": "119/10", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "250", "EXIF ExifVersion": "0230", "EXIF DateTimeOriginal": "2014:06:13 20:50:35", "EXIF DateTimeDigitized": "2014:06:13 20:50:35", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "4", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "18/5", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash fired, auto mode", "EXIF FocalLength": "53/10", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "4608", "EXIF ExifImageLength": "3456", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "0", "EXIF FocalLengthIn35mmFilm": "30", "EXIF SceneCaptureType": "Standard", "EXIF GainControl": "High gain up", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF SubjectDistanceRange": "0", "EXIF Padding": "[]", "EXIF OffsetSchema": "4168"}