Editing Scorpion (section)

==Evolution==

===Fossil record===

[[File:Palaeophonus nuncius NRM PAL Ar0032235.jpg|thumb|Fossil of ''[[Palaeophonus|Palaeophonus nuncius]]'', a [[Silurian]] scorpion from Sweden]]

Scorpion [[fossil]]s have been found in many [[strata]], including marine [[Silurian]] and estuarine [[Devonian]] deposits, coal deposits from the [[Carboniferous Period]] and in [[amber]]. Whether the early scorpions were marine or terrestrial has been debated, and while they had [[book lung]]s like modern terrestrial species,<ref name="Howard Edgecombe 2019"/><ref>{{cite journal |last1=Scholtz |first1=Gerhard |last2=Kamenz |first2=Carsten |title=The Book Lungs of Scorpiones and Tetrapulmonata (Chelicerata, Arachnida): Evidence for Homology and a Single Terrestrialisation Event of a Common Arachnid Ancestor |year=2006 |journal=Zoology |volume=109 |issue=1 |pages=2–13 |pmid=16386884 |doi=10.1016/j.zool.2005.06.003 |bibcode=2006Zool..109....2S }}</ref><ref>{{cite journal |last1=Dunlop |first1=Jason A. |last2=Tetlie |first2=O. Erik |last3=Prendini |first3=Lorenzo |doi=10.1111/j.1475-4983.2007.00749.x |title=Reinterpretation of the Silurian Scorpion ''Proscorpius osborni'' (Whitfield): Integrating Data from Palaeozoic and Recent Scorpions |year=2008 |journal=Palaeontology |volume=51 |issue=2 |pages=303–320|bibcode=2008Palgy..51..303D |doi-access=free }}</ref><ref>{{cite journal |last1=Kühl |first1=G. |first2=A. |last2=Bergmann |first3=J. |last3=Dunlop |first4=R. J. |last4=Garwood |first5=J. |last5=Rust |doi=10.1111/j.1475-4983.2012.01152.x |title=Redescription and Palaeobiology of ''Palaeoscorpius devonicus'' Lehmann, 1944 from the Lower Devonian Hunsrück Slate of Germany |year=2012 |journal=Palaeontology |volume=55 |issue=4 |pages=775–787|bibcode=2012Palgy..55..775K |doi-access=free }}</ref> the most basal such as ''[[Eramoscorpius]]'' were originally considered as still aquatic,<ref>{{cite journal |last1=Waddington |first1=Janet |last2=Rudkin |first2=David M. |last3=Dunlop |first3=Jason A. |title=A new mid-Silurian aquatic scorpion—one step closer to land? |journal=Biology Letters |date=January 2015 |volume=11 |issue=1 |pages=20140815 |doi=10.1098/rsbl.2014.0815|pmid=25589484 |pmc=4321148 }}</ref> until it was found that ''Eramoscorpius'' had book lungs.<ref>{{Cite journal |last1=Haug |first1=C. |last2=Wagner |first2=P. |last3=Haug |first3=J.T. |date=2019-12-31 |title=The evolutionary history of body organisation in the lineage towards modern scorpions |journal=Bulletin of Geosciences |pages=389–408 |doi=10.3140/bull.geosci.1750 |issn=1802-8225 |doi-access=free}}</ref> Over 100 fossil species of scorpion have been described.<ref name=Siri>{{cite book |last1=Dunlop |first1=J. A. |last2=Penney |first2=D. |year=2012 |title=Fossil Arachnids |publisher=Siri Scientific Press |page=23 |isbn=978-0956779540}}</ref> The oldest found as of 2021 is ''[[Dolichophonus|Dolichophonus loudonensis]]'', which lived during the Silurian, in present-day Scotland.<ref>{{Cite journal|last1=Anderson|first1=Evan P.|last2=Schiffbauer|first2=James D.|last3=Jacquet|first3=Sarah M.|last4=Lamsdell|first4=James C.|last5=Kluessendorf|first5=Joanne|last6=Mikulic|first6=Donald G.|date=2021|title=Stranger than a scorpion: a reassessment of Parioscorpio venator, a problematic arthropod from the Llandoverian Waukesha Lagerstätte|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/pala.12534|journal=Palaeontology|language=en|volume=64|issue=3|pages=429–474|doi=10.1111/pala.12534|bibcode=2021Palgy..64..429A |s2cid=234812878|issn=1475-4983|access-date=20 April 2021|archive-date=20 April 2021|archive-url=https://web.archive.org/web/20210420145034/https://onlinelibrary.wiley.com/doi/abs/10.1111/pala.12534|url-status=live|url-access=subscription}}</ref> ''[[Gondwanascorpio]]'' from the Devonian is among the earliest-known terrestrial animals on the [[Gondwana]] supercontinent.<ref>{{cite journal |last=Gess |first=R. W. |year=2013 |title=The Earliest Record of Terrestrial Animals in Gondwana: a Scorpion from the Famennian (Late Devonian) Witpoort Formation of South Africa |journal=[[African Invertebrates]] |volume=54 |issue=2 |pages=373–379 |url=http://africaninvertebrates.org/ojs/index.php/AI/article/view/284 |doi=10.5733/afin.054.0206 |doi-access=free |bibcode=2013AfrIn..54..373G |access-date=28 August 2013 |archive-date=6 September 2013 |archive-url=https://web.archive.org/web/20130906073206/http://africaninvertebrates.org/ojs/index.php/AI/article/view/284 |url-status=usurped }}</ref> Some Palaeozoic scorpions possessed [[compound eye]]s similar to those of eurypterids.<ref>{{cite journal | pmid=31780700 | year=2019 | last1=Schoenemann | first1=B. | last2=Poschmann | first2=M. | author3=Clarkson ENK | title=Insights into the 400 million-year-old eyes of giant sea scorpions (Eurypterida) suggest the structure of Palaeozoic compound eyes | journal=Scientific Reports | volume=9 | issue=1 | page=17797 | doi=10.1038/s41598-019-53590-8 | pmc=6882788 | bibcode=2019NatSR...917797S }}</ref> The [[Triassic]] fossils ''[[Protochactas]]'' and ''[[Protobuthus]]'' belong to the modern clades [[Chactoidea]] and [[Buthoidea]] respectively, indicating that the [[crown group]] of modern scorpions had emerged by this time.<ref>{{Cite journal |last1=Magnani, Fabio |last2=Stockar, Rudolf |last3=Lourenço, Wilson R. |date=2022 |others=Lionel Delaunay |title=Une nouvelle famille, genre et espèce de scorpion fossile du Calcaire de Meride (Trias Moyen) du Mont San Giorgio (Suisse)A new family, genus and species of fossil scorpion from the Meride Limestone (Middle Triassic) of Monte San Giorgio (Switzerland) |journal=Faunitaxys |volume=10 |issue=24 |url=https://hal.archives-ouvertes.fr/hal-03660445v1 |language=en |pages=1–7 |doi=10.57800/FAUNITAXYS-10(24)}}</ref>

===Phylogeny===

The Scorpiones are a [[clade]] within the pulmonate [[Arachnida]] (those with book lungs). Arachnida is placed within the [[Chelicerata]], a subphylum of [[Arthropoda]] that contains [[sea spider]]s and [[horseshoe crab]]s, alongside terrestrial animals without book lungs such as [[tick]]s and [[harvestmen]].<ref name="Howard Edgecombe 2019"/> The extinct [[Eurypterida]], sometimes called sea scorpions, though they were not all marine, are not scorpions; their grasping pincers were [[chelicerae]], not [[Homology (biology)|homologous]] with the pincers (second appendages) of scorpions.<ref>{{cite web |last=Waggoner |first=B. M. |title=Eurypterida: Morphology |url=https://ucmp.berkeley.edu/arthropoda/chelicerata/eurypteridmm.html |publisher=University of California Museum of Paleontology Berkeley |access-date=20 October 2020 |date=12 October 1999 |archive-date=23 October 2020 |archive-url=https://web.archive.org/web/20201023013411/https://ucmp.berkeley.edu/arthropoda/chelicerata/eurypteridmm.html |url-status=live }}</ref> Scorpiones is [[Sister taxon|sister]] to the [[Tetrapulmonata]], a terrestrial group of pulmonates containing the [[spider]]s and whip scorpions. This 2019 [[cladogram]] summarizes:<ref name="Howard Edgecombe 2019"/>

{{clade
|label1=[[Chelicerata]]
|1={{clade
   |1=[[Pycnogonida]] (sea spiders) [[File:Nymphon signatum 194389384 (white background).jpg|90px]]
   |label2=[[Prosomapoda]]
   |2={{clade
      |1=[[Xiphosura]] (horseshoe crabs) [[File:Limulus polyphemus (aquarium) (white background).jpg|70px]]
      |2={{clade
         |1=†[[Eurypterida]] (sea scorpions) <span style="{{MirrorH}}">[[File:Eurypterus Paleoart (no background).png|70 px]]</span>
         |label2=[[Arachnida]]
         |2={{clade
            |label1=Non-pulmonates
            |1=([[ticks]], [[harvestmen]], etc) [[File:Ixodes scapularis P1170301a (white background).png|70px]]
            |label2=pulmonates
            |2={{clade
               |label1='''Scorpiones'''
               |1=[[File:Buthus_mariefranceae_(10.3897-zookeys.686.12206)_Figure_1.jpg|65px]]
               |label2=[[Tetrapulmonata]]
               |2={{clade
                  |1=[[Araneae]] (spiders) [[File:Aptostichus simus Monterey County.jpg|70px]]
                  |2=Pedipalpi ([[whip scorpions]], etc) [[File:Whip Scorpion body (9672115742) (white background).png|80px]]
                  }}
               }}
            }}
         }}
      }}
   }}
}}

Recent studies place [[pseudoscorpion]]s as the sister group of scorpions in the clade Panscorpiones, which together with Tetrapulmonata makes up the clade Arachnopulmonata.<ref>{{Cite journal|url=https://www.biorxiv.org/content/10.1101/2020.11.18.389098v1|title=Taxonomic sampling and rare genomic changes overcome long-branch attraction in the phylogenetic placement of pseudoscorpions|first1=Andrew Z.|last1=Ontano|first2=Guilherme|last2=Gainett|first3=Shlomi|last3=Aharon|first4=Jesús A.|last4=Ballesteros|first5=Ligia R.|last5=Benavides|first6=Kevin F.|last6=Corbett|first7=Efrat|last7=Gavish-Regev|first8=Mark S.|last8=Harvey|first9=Scott|last9=Monsma|first10=Carlos E.|last10=Santibáñez-López|first11=Emily V. W.|last11=Setton|first12=Jakob T.|last12=Zehms|first13=Jeanne A.|last13=Zeh|first14=David W.|last14=Zeh|first15=Prashant P.|last15=Sharma|journal=Molecular Biology and Evolution|volume=38|issue=6|date=June 2021|pages=2446–2467|doi=10.1093/molbev/msab038|pmid=33565584 |pmc=8136511 }}</ref>

The internal [[phylogeny]] of the scorpions has been debated,<ref name="Howard Edgecombe 2019">{{cite journal |last1=Howard |first1=Richard J. |last2=Edgecombe |first2=Gregory D. |last3=Legg |first3=David A. |last4=Pisani |first4=Davide |last5=Lozano-Fernandez |first5=Jesus |title=Exploring the Evolution and Terrestrialization of Scorpions (Arachnida: Scorpiones) with Rocks and Clocks |journal=Organisms Diversity & Evolution |volume=19 |issue=1 |year=2019 |pages=71–86 |issn=1439-6092 |doi=10.1007/s13127-019-00390-7 |doi-access=free|bibcode=2019ODivE..19...71H |hdl=10261/217081 |hdl-access=free }}</ref> but [[genomic]] analysis consistently places the [[Bothriuridae]] as sister to a clade consisting of Scorpionoidea and [[Chactoidea]]. The scorpions diversified between the Devonian and the early [[Carboniferous]]. The main division is into the clades Buthida and Iurida. The Bothriuridae diverged starting before temperate Gondwana broke up into separate land masses, completed by the [[Jurassic]]. The Iuroidea and Chactoidea are both seen not to be single clades, and are shown as "[[paraphyletic]]" (with quotation marks) in this 2018 cladogram.<ref name="Sharma Baker 2018">{{cite journal |last1=Sharma |first1=Prashant P. |last2=Baker |first2=Caitlin M. |last3=Cosgrove |first3=Julia G. |last4=Johnson |first4=Joanne E. |last5=Oberski |first5=Jill T. |last6=Raven |first6=Robert J. |last7=Harvey |first7=Mark S. |last8=Boyer |first8=Sarah L. |last9=Giribet |first9=Gonzalo |title=A Revised Dated Phylogeny of Scorpions: Phylogenomic Support for Ancient Divergence of the Temperate Gondwanan Family Bothriuridae |journal=Molecular Phylogenetics and Evolution |volume=122 |year=2018 |pages=37–45 |issn=1055-7903 |doi=10.1016/j.ympev.2018.01.003 |pmid=29366829 |doi-access=free |bibcode=2018MolPE.122...37S }}</ref>

{{clade
|label1='''Scorpiones'''
|1={{clade
   |label1=Buthida
   |1={{clade
      |1={{clade
         |1=[[Chaeriloidea]] <!--(53 spp.)--> [[File:Chaerilus pseudoconchiformus male (cropped).jpg|55px]]
         |2=[[Pseudochactoidea]] <!--(9 spp.)--> [[File:Vietbocap canhi (white background).jpg|45px]]
         }}
      |2=[[Buthoidea]] <!--(1209 spp.)--> [[File:Buthus mariefranceae (10.3897-zookeys.686.12206) Figure 1.jpg|65px]]
      }}
   |label2=Iurida<!--Parvorder-->
   |2={{clade
      |1="[[Iuroidea]]" (part) <!--14 spp.-->
      |2={{clade
         |1=[[Bothriuroidea]] <!--(158 spp.)--> [[File:Cercophonius squama.jpg|80px]]
         |2={{clade
            |1={{clade
               |1={{clade
                  |1="[[Chactoidea]]" (part)
                  |2="[[Iuroidea]]" (part)
                  }}
               |2="[[Chactoidea]]" (part)
               }}
            |2=[[Scorpionoidea]] <!--(183 spp.)--> <span style="{{MirrorH}}">[[File:Female Emperor Scorpion.jpg|75px]]</span>
            }}
         }}
      }}
   }}
}}

===Taxonomy===

{{main|Taxonomy of scorpions}}

[[Carl Linnaeus]] described six species of scorpion in his genus ''Scorpio'' in 1758 and 1767; three of these are now considered [[Valid name (zoology)|valid]] and are called ''[[Scorpio maurus]]'', ''[[Androctonus australis]]'', and ''[[Euscorpius carpathicus]]''; the other three are dubious names. He placed the scorpions among his "Insecta aptera" (wingless insects), a group that included [[Crustacean|Crustacea]], Arachnida and [[Myriapoda]].<ref>{{cite journal |last1=Fet |first1=V. |last2=Braunwalder |first2=M. E. |last3=Cameron |first3=H. D. |title=Scorpions (Arachnida, Scorpiones) Described by Linnaeus |journal=Bulletin of the British Arachnological Society |date=2002 |volume=12 |issue=4 |pages=176–182 |url=http://britishspiders.org.uk/bulletin/120405.pdf |access-date=20 October 2020 |archive-date=26 September 2020 |archive-url=https://web.archive.org/web/20200926182646/http://britishspiders.org.uk/bulletin/120405.pdf |url-status=live }}</ref> In 1801, [[Jean-Baptiste Lamarck]] divided up the "Insecta aptera", creating the [[taxon]] Arachnides for spiders, scorpions, and [[Mite|acari (mites and ticks)]], though it also contained the [[Thysanura]], Myriapoda and parasites such as [[lice]].<ref name="Burmeister 1836">{{cite book |last1=Burmeister |first1=Carl Hermann C. |last2=Shuckard |first2=W. E. (trans) |title=A Manual of Entomology |url=https://books.google.com/books?id=g9sDAAAAQAAJ&pg=PA613 |year=1836 |pages=613ff |access-date=20 October 2020 |archive-date=31 May 2021 |archive-url=https://web.archive.org/web/20210531031222/https://books.google.com/books?id=g9sDAAAAQAAJ&pg=PA613 |url-status=live }}</ref> German [[arachnologist]] [[Carl Ludwig Koch]] created the order Scorpiones in 1837. He divided it into four families, the six-eyed scorpions "Scorpionides", the eight-eyed scorpions "Buthides", the ten-eyed scorpions "Centrurides", and the twelve-eyed scorpions "Androctonides".<ref>{{cite book |last=Koch |first=Carl Ludwig |title=Übersicht des Arachnidensystems |date=1837 |publisher=C. H. Zeh |pages=86–92 |url=https://archive.org/details/bersichtdesara1518371850koch/page/n91/mode/2up?q=Scorpiones |language=de}}</ref>

More recently, some twenty-two families containing over 2,500 species of scorpions have been [[Species description|described]], with many additions and much reorganization of taxa in the 21st century.<ref name="Rein 2020"/><ref name="Howard Edgecombe 2019"/><ref>{{cite web |url=http://kovarex.com/scorpio/pdf/scorpions-Kovarik-2009.pdf |first=František |last=Kovařík |year=2009 |title=Illustrated Catalog of Scorpions, Part I |access-date=22 January 2011 |archive-date=26 October 2010 |archive-url=https://web.archive.org/web/20101026163042/http://kovarex.com/scorpio/pdf/scorpions-Kovarik-2009.pdf |url-status=live }}</ref> There are over 100 described taxa of fossil scorpions.<ref name=Siri/> This classification is based on Soleglad and Fet (2003),<ref>{{cite journal |last1=Soleglad |first1=Michael E. |last2=Fet |first2=Victor |year=2003 |title=High-level Systematics and Phylogeny of the Extant Scorpions (Scorpiones: Orthosterni) |journal=[[Euscorpius (journal)|Euscorpius]] |volume=11 |pages=1–175 |url=http://www.science.marshall.edu/fet/euscorpius/pubs.htm |format=multiple parts |access-date=13 June 2008 |archive-date=8 December 2019 |archive-url=https://web.archive.org/web/20191208071547/http://www.science.marshall.edu/fet/euscorpius/pubs.htm |url-status=live }}</ref> which replaced Stockwell's older, unpublished classification.<ref>{{cite thesis |last=Stockwell |first=Scott A. |title=Revision of the Phylogeny and Higher Classification of Scorpions (Chelicerata) |year=1989 |publisher=[[University of California, Berkeley]]|type=PhD thesis}}</ref> Further taxonomic changes are from papers by Soleglad et al. (2005).<ref name=Soleglad2005>{{cite journal |last1=Soleglad |first1=Michael E. |last2=Fet |first2=Victor |last3=Kovařík |first3=F. |year=2005 |title=The Systematic Position of the Scorpion Genera ''Heteroscorpion'' Birula, 1903 and ''Urodacus'' Peters, 1861 (Scorpiones: Scorpionoidea) |journal=[[Euscorpius (journal)|Euscorpius]] |volume=20 |pages=1–38 |url=http://www.science.marshall.edu/fet/euscorpius/p2005_20.pdf |access-date=13 June 2008 |archive-date=16 December 2008 |archive-url=https://web.archive.org/web/20081216234048/http://www.science.marshall.edu/fet/euscorpius/p2005_20.pdf |url-status=live }}</ref><ref>{{cite journal |last1=Fet |first1=Victor |last2=Soleglad |first2=Michael E. |year=2005 |title=Contributions to Scorpion Systematics. I. On Recent Changes in High-level Taxonomy |journal=[[Euscorpius (journal)|Euscorpius]] |issue=31 |pages=1–13 |url=http://www.science.marshall.edu/fet/euscorpius/p2005_31.pdf |issn=1536-9307 |access-date=7 April 2010 |archive-date=26 April 2018 |archive-url=https://web.archive.org/web/20180426135453/http://www.science.marshall.edu/fet/euscorpius/p2005_31.pdf |url-status=live }}</ref>

The extant taxa to the [[taxonomic rank|rank]] of [[family (biology)|family]] (numbers of species in parentheses<ref name="Rein 2020">{{cite web |title=The Scorpion Files |url=https://www.ntnu.no/ub/scorpion-files/index.php |publisher=Jan Ove Rein |access-date=15 August 2020 |archive-date=3 October 2020 |archive-url=https://web.archive.org/web/20201003094246/https://www.ntnu.no/ub/scorpion-files/index.php |url-status=live }}</ref>) are:

; Order Scorpiones

[[File:StripedBarkScorpion.jpg|thumb|upright|''[[Striped Bark Scorpion|Centruroides vittatus]]'', the striped bark scorpion, a member of [[Buthidae]], the largest family of scorpions]]

[[File:Asian forest scorpion in Khao Yai National Park.JPG|thumb|right|upright=0.6|''[[Heterometrus laoticus]]'', the Vietnam forest scorpion, a member of the family [[Scorpionidae]]]]

{{div col begin|colwidth=40em}}
<!--* Infraorder [[Orthosterni]] <small>[[Reginald Innes Pocock|Pocock]], 1911</small>-->
* Parvorder [[Pseudochactida]] <small>[[Michael E. Soleglad|Soleglad]] & [[Victor Fet|Fet]], 2003</small>
<!----------------------------------------------->
** Superfamily [[Pseudochactoidea]] <small>[[Alexander V. Gromov|Gromov]], 1998</small>
*** Family [[Pseudochactidae]] <small>[[Alexander V. Gromov|Gromov]], 1998</small> (1 sp.) (Central Asian scorpions of semi-[[savanna]] habitats)
<!----------------------------------------------->
* Parvorder [[Buthida]] <small>[[Michael E. Soleglad|Soleglad]] & [[Victor Fet|Fet]], 2003</small>
<!----------------------------------------------->
** Superfamily [[Buthoidea]] <small>[[C. L. Koch]], 1837</small>
*** Family [[Buthidae]] <small>[[C. L. Koch]], 1837</small> (1209 spp.) (thick-tailed scorpions, including the most dangerous species)
*** Family [[Microcharmidae]] <small>[[Wilson R. Lourenço|Lourenço]], 1996, 2019</small> (17 spp.) (African scorpions of humid forest leaf litter)
<!----------------------------------------------->
* Parvorder [[Chaerilida]] <small>[[Michael E. Soleglad|Soleglad]] & [[Victor Fet|Fet]], 2003</small>
<!----------------------------------------------->
** Superfamily [[Chaeriloidea]] <small>[[Reginald Innes Pocock|Pocock]], 1893</small>
*** Family [[Chaerilidae]] <small>[[Reginald Innes Pocock|Pocock]], 1893</small> (51 spp.) (South and Southeast Asian scorpions of non-arid places)

<!----------------------------------------------->
* Parvorder [[Iurida]] <small>[[Michael E. Soleglad|Soleglad]] & [[Victor Fet|Fet]], 2003</small>
<!----------------------------------------------->
** Superfamily [[Chactoidea]] <small>[[Reginald Innes Pocock|Pocock]], 1893</small>
*** Family [[Akravidae]] <small>Levy, 2007</small> (1 sp.) (cave-dwelling scorpions of Israel)
*** Family [[Belisariidae]] <small>[[Wilson R. Lourenço|Lourenço]], 1998</small> (3 spp.) (cave-related scorpions of Southern Europe)
*** Family [[Chactidae]] <small>[[Reginald Innes Pocock|Pocock]], 1893</small> (209 spp.) (New World scorpions, membership under revision)
*** Family [[Euscorpiidae]] <small>[[Malcolm Laurie|Laurie]], 1896</small> (170 spp.) (harmless scorpions of the Americas, Eurasia, and North Africa)
*** Family [[Superstitioniidae]] <small>[[Herbert Stahnke|Stahnke]], 1940</small> (1 sp.) (cave scorpions of Mexico and Southwestern United States)
*** Family [[Troglotayosicidae]] <small>[[Wilson R. Lourenço|Lourenço]], 1998</small> (4 spp.) (cave-related scorpions of South America)
*** Family [[Typhlochactidae]] <small>Mitchell, 1971</small> (11 spp.) (cave-related scorpions of Eastern Mexico)
*** Family [[Vaejovidae]] <small>[[Tord Tamerlan Teodor Thorell|Thorell]], 1876</small> (222 spp.) (New World scorpions)
<!----------------------------------------------->
** Superfamily [[Iuroidea]] <small>[[Tord Tamerlan Teodor Thorell|Thorell]], 1876</small>
*** Family [[Caraboctonidae]] <small>[[Karl Kraepelin|Kraepelin]], 1905</small> (23 spp.) (hairy scorpions)
*** Family [[Hadruridae]] <small>[[Herbert Stahnke|Stahnke]], 1974</small> (9 spp.) (large North American scorpions)
*** Family [[Iuridae]] <small>[[Tord Tamerlan Teodor Thorell|Thorell]], 1876</small> (21 spp.) (scorpions with a large tooth on inner side of moveable claw)
<!----------------------------------------------->
** Superfamily [[Scorpionoidea]] <small>[[Latreille]], 1802</small>
*** Family [[Bothriuridae]] <small>[[Eugène Simon|Simon]], 1880</small> (158 spp.) (Southern hemisphere tropical and temperate scorpions)
*** Family [[Hemiscorpiidae]] <small>[[Reginald Innes Pocock|Pocock]], 1893</small> (16 spp.) (rock, creeping, or tree scorpions of the Middle East)
*** Family [[Hormuridae]] <small>[[Malcolm Laurie|Laurie]], 1896</small> (92 spp.) (flattened, crevice-living scorpions of Southeast Asia and Australia)
*** Family [[Rugodentidae]] <small>Bastawade et al., 2005</small> (1 sp.) (burrowing scorpions of India)
*** Family [[Scorpionidae]] <small>[[Latreille]], 1802</small> (183 spp.) (burrowing or pale-legged scorpions)
*** Family [[Diplocentridae]] <small>[[Ferdinand Karsch|Karsch]], 1880</small> (134 spp.) (closely related to and sometimes placed in Scorpionidae, but have spine on telson)
*** Family [[Heteroscorpionidae]] <small>[[Karl Kraepelin|Kraepelin]], 1905</small> (6 spp.) (scorpions of Madagascar)

{{div col end}}