{{Short description|Genus of scorpions}} {{Automatic taxobox | image = Parabuthus villosus, b, Usakos.jpg | image_caption = A wandering male ''[[Parabuthus villosus|P. villosus]]'' in Namibia – unique in its size and diurnal habits<ref name=Prend2004/> | taxon = Parabuthus | authority = [[Reginald Innes Pocock|Pocock]], 1890 | type_species = ''[[Parabuthus leiosoma|P. leiosoma]]''<ref name=Prend2004/> | type_species_authority = ([[Christian Gottfried Ehrenberg|Ehrenberg]] 1828) | diversity_link = Parabuthus#diversity | diversity_ref = <ref name=Prend2004/><ref name=biodiv/> | diversity = Some 27 to 28 species }}
'''''Parabuthus''''', commonly known as the '''thick-tailed scorpion''', is a [[genus]] of large and highly venomous [[Afrotropical realm|Afrotropical]] [[scorpion]]s, that show a preference for areas of low [[rainfall]].<ref name=Prend2004>{{cite journal |last=Prendini |first=Lorenzo |title=The systematics of southern African Parabuthus |journal=The Journal of Arachnology |year=2004 |volume=32 |pages=109–186 |url=http://www.americanarachnology.org/JoA_free/JoA_v32_n1/arac-032-01-0109.pdf |access-date=7 October 2012 |doi=10.1636/h03-17 |s2cid=86647224 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304111049/http://www.americanarachnology.org/JoA_free/JoA_v32_n1/arac-032-01-0109.pdf |url-status=dead }}</ref><ref name=Leeming>{{cite book |author=Jonathan Leeming |year=2003 |title=Scorpions of Southern Africa |publisher=Struik |isbn=978-1-86872-804-6 |chapter=Southern African species |pages=49–50 }}</ref> Their stings are medically important and human fatalities have been recorded.<ref>Larsen, Norman. Biodiversity Explorer, IZIKO. Scorpion stings and venoms [http://www.biodiversityexplorer.org/arachnids/scorpions/stings_and_venoms.htm]</ref>
==Characteristics== They have thick and strong tails, with typically a rough surface to the first (proximal) and sometimes second segment, that is used to produce a warning<ref name=biodiv>{{cite web|last=Norman Larsen |title=Parabuthus (burrowing thick-tailed scorpions) |url=http://www.biodiversityexplorer.org/arachnids/scorpions/buthidae/parabuthus.htm |publisher=biodiversityexplorer |access-date=3 October 2012}}</ref> sound when rubbed against the sting (save ''[[Parabuthus distridor|P. distridor]]'').<ref name=Prend2004/><ref name=Leeming/> Their thick tails are also employed in excavating their shallow burrows, as several are adapted to sandy environments.<ref name=biodiv/> Some flatter-bodied species, however, take refuge in rock crevasses.<ref name=Leeming/>
Due to their stings' quick-acting venom, they rely to lesser extent on their slender pinchers (chelae) to hold onto prey.<ref name=biodiv/> Three species, ''[[Parabuthus schlechteri|P. schlechteri]]'', ''[[Parabuthus transvaalicus|P. transvaalicus]]'', and ''[[Parabuthus villosus|P. villosus]]'' are thought to be able to spray venom from their tails. These three are also the largest [[Buthidae|buthids]] in the world,<ref name=biodiv/> reaching lengths up to 140 mm and masses up to 14 g.<ref name=Prend2004/>
Other consistent features include a dorsal head covering ([[carapace]]) that lacks [[wikt:granule|granular]] ridges (carinae), while the [[Metasoma|tail]]'s upper coverings ([[Tergum|tergites]]) have only one inconspicuous middle (median) ridge.<ref name=Prend2004/> The pectine teeth nearest the body in females are enlarged and dilated (''[[Parabuthus granulatus|P. granulatus]]'' and ''[[Parabuthus kalaharicus|P. kalaharicus]]'' excepting), and the lower tarsi (third distal segment) of the front four legs are equipped with bristle combs.<ref group=n>Also referred to as macro[[seta]]l combs or "sand combs".</ref> The ventrosubmedian ridges in the fourth tail segment disappear away from the body, and the ventrolateral ridges of the fifth segment include distinctly spined or lobed [[Process (anatomy)|processes]] near their distal ends.<!--attempt at non-technical description--><ref name=Prend2004/>
==Diversity== Most of the species, some 20<ref name=Prend2004/> of the total of 28, are endemic to southern Africa,<ref name=biodiv/> but they range through eastern Africa to the Arabian Peninsula.<ref name=biodiv/>
===Selected species=== * ''[[Parabuthus brevimanus]]'' * ''[[Parabuthus capensis]]'' * ''[[Parabuthus granulatus]]'' * ''[[Parabuthus laevipes]]'' * ''[[Parabuthus liosoma]]'' * ''[[Parabuthus mossambicensis]]'' * ''[[Parabuthus namibensis]]'' * ''[[Parabuthus raudus]]'' * ''[[Parabuthus schlechteri]]'' * ''[[Parabuthus stridulus]]'' * ''[[Parabuthus transvaalicus]]'' * ''[[Parabuthus villosus]]''
==Phylogenetics== Its nearest relations are the Afrotropical buthid genera ''[[Grosphus]]'' and ''[[Uroplectes]]'', which lack the distinct stridulatory surfaces.<ref name=Prend2004/> The following [[cladogram]] illustrates relationships among 20 ''Parabuthus'' and these outlying genera, according to an analysis done by Lorenzo Prendini et al. 2003. Some recently described species (''P. cimrmani'', ''P. eritreaensis'', ''P. truculentus'' and ''P. zavattarii'') were not considered in the investigation, so that their positions within this system remain unresolved. {{Clade |1=''[[Grosphus madagascariensis]]'' |2={{Clade |1=''[[Uroplectes triangulifer]]'' |2={{Clade |1={{Clade |1={{Clade |1=''P. brevimanus'' |2={{Clade |1={{Clade |1=''P. distridor'' |2=''P. kuanyamarum''}} |2={{Clade |1=''P. gracilis'' |2=''P. nanus''}} }} }} |2={{Clade |1={{Clade |1=''P. granulatus'' |2=''P. kalaharicus''}} |2={{Clade |1=''P. namibensis '' |2={{Clade |1=''P. laevifrons'' |2=''P. stridulus''}} }} }} }} |2={{Clade |1={{Clade |1=''P. liosoma'' |2={{Clade |1=''P. heterurus'' |2={{Clade |1=''P. granimanus'' |2=''P. hunteri'' }} }} }} |2={{Clade |1={{Clade |1=''P. capensis'' |2={{Clade |1=''P. muelleri'' |2={{Clade |1=''P. calvus'' |2=''P. pallidus'' |3=''P. planicauda''}} }} }} |2={{Clade |1=''P. mossambicensis'' |2={{Clade |1=''P. kraepelini'' |2={{Clade |1={{Clade |1=''P. raudus'' |2=''P. schlechteri''}} |2={{Clade |1=''P. transvaalicus'' |2=''P. villosus''}} }} }} }} }} }} }} }} }}
==See also== *[[Parabutoxin]], the potassium channel inhibitor isolated from the venom of some ''Parabuthus'' species
==Notes== {{Reflist|group=n}}
==References== {{Reflist|2}}
{{Taxonbar|from=Q146377}} {{Authority control}}
[[Category:Parabuthus| ]] [[Category:Scorpion genera]] [[Category:Arachnids of Africa]]