Uropygi

{{Short description|Order of arachnids known as whip scorpions}} {{Use Oxford spelling|date = November 2017}} {{Use dmy dates|date=March 2023}} {{Automatic taxobox | fossil_range = {{Fossil range|Carboniferous|present}} | name = Whip scorpions, vinegaroons | image = Typopeltis crucifer at Fuxing, Taoyuan 2022-06-12 (cropped).jpg | image_caption = ''Typopeltis crucifer'' | taxon = Uropygi | authority = Thorell, 1883<ref name=Harv03> {{cite book |last1=Harvey |first1=Mark S. |year=2003 |contribution=Uropygi |title=Catalogue of the Smaller Arachnid Orders of the World: Amblypygi, Uropygi, Schizomida, Palpigradi, Ricinulei and Solifugae |place=Canberra, AU |publisher=CSIRO Publishing |isbn=978-0-643-09007-1 |doi=10.1071/9780643090071 }} </ref><ref name=WAM> {{cite web |title=Uropygi {{small|(Thorell, 1883)}} |series=Field Guides & Catalogues |website=Western Australian Museum |publisher=Western Australian Museum, Government of Western Australia |url=https://museum.wa.gov.au/catalogues-beta/whip-scorpions/order/uropygi |access-date=2023-03-10 }} </ref> | synonyms = Thelyphonida Latreille, 1804 (as Thélyphone) | synonyms_ref = <ref name=Harv03/><ref name=WAM/> | diversity_link = List of Thelyphonidae species | diversity = {{circa|27}} genera, over 100 species | subdivision_ranks = Families | subdivision = *Thelyphonidae }}

'''Uropygi''' is an arachnid order comprising invertebrates commonly known as '''whip scorpions''' or '''vinegaroons''' (also spelled '''vinegarroons''' and '''vinegarones'''). They are often called '''uropygids'''. The name "whip scorpion" refers to their resemblance to true scorpions and possession of a whiplike tail, and "vinegaroon" refers to their ability when attacked to discharge an offensive, vinegar-smelling liquid, which contains acetic acid. The order may also be called Thelyphonida. Both names, Uropygi and Thelyphonida, may be used either in a narrow sense for the order of whip scorpions, or in a broad sense which includes the order Schizomida.{{efn| For clarity, ''sensu stricto'' or ''s.s.'' may be added to specify the narrow sense, and ''sensu lato'' or ''s.l.'' added to specify the broad sense. When these additions are omitted, the names Uropygi and Thelyphonida are ambiguous. }}

==Taxonomy== Carl Linnaeus first described a whip scorpion in 1758, although he did not distinguish it from what are now regarded as different kinds of arachnid, calling it ''Phalangium caudatum''. ''Phalangium'' is now used as a name for a genus of harvestmen (Opiliones). In 1802, Pierre André Latreille was the first to use a genus name solely for whip scorpions, namely ''Thelyphonus''.<ref name=Harv02/><ref name=Latr02/> Latreille later explained the name as meaning "''{{lang|fr|qui tue}}''", meaning "who kills".<ref name=Latr04/>{{efn| In Greek {{lang|grc|{{math|φόνος}}}}, ''phonos'', means "murder", while {{lang|grc|{{math|φονός}} }}, with final accent, can be an adjective meaning "murderous", but also a noun meaning "murderess"; Latreille did not account for the element {{lang|grc|{{math|θῆλυς}}}}, ''thelys'', meaning "female". }} One name for the order, Thelyphonida, is based on Latreille's genus name. It was first used, as the French {{lang|fr|Thélyphone}}, by Latreille in 1804,<ref name=Harv03/> and later by Octavius Pickard-Cambridge in 1872 (with the spelling Thelyphonidea).<ref name=Camb72/>

The alternative name, Uropygi, was first used by Tamerlan Thorell in 1883.<ref name=Harv03/> It means "tail rump", from Ancient Greek {{lang|el|{{math|οὐροπύγιον}} }} (''{{lang|el|ouropygion}}''),<ref>{{cite book |author=Aristotele |url=https://books.google.com/books?id=sUfySpLBb2wC&pg=PA109-IA3 |title=De Anim. Hist. | date=28 November 2023 |at=Lib: IV Cap: I}}</ref> from {{lang|grc|{{math|οὐρά}} }} (''{{lang|el|oura}}'') "tail" and {{lang|grc|{{math|πυγή}} }} (''{{lang|el|pygē}}'') "rump" referring to the whip-like flagellum on the end of the pygidium, a small plate made up of the last three segments of the abdominal exoskeleton.

The classification and scientific name used for whip scorpions varies. Originally, Amblypygi (whip spiders), Uropygi and Schizomida (short-tailed whipscorpions) formed a single order of arachnids, Pedipalpi. Pedipalpi was later divided into two orders, Amblypygi and Uropygi (or Uropygida). Schizomida was then split off from Uropygi into a separate order.<ref name=Garw/> The remainder has either continued to be called by the same name, Uropygi,<ref name=Harv02/> possibly distinguished as Uropygi ''sensu stricto'', or called Thelyphonida.<ref name=Garw/> When the name Uropygi is used for the whip scorpions, the clade containing Uropygi and Schizomida may be called Thelyphonida,<ref name=Clou17/><ref>{{fossilworks |id=276198 |title=Order Thelyphonida {{small|(Latreille, 1804)}} (whip scorpion) |access-date=2023-03-10}}</ref> or Thelyphonida ''s.l.'' Conversely, when the name Thelyphonida is used for the whip scorpions alone, the parent clade may be called Uropygi,<ref name=RuizVale17>{{Cite journal |last1=Ruiz |first1=Gustavo R.S. |last2=Valente |first2=Roberta M. |date=2017 |title=First description of the male genitalia in a short-tailed whipscorpion (Arachnida: Schizomida), description of the female, and comments on pygidial glands and cuticular ultrastructure of ''Surazomus algodoal'' Ruiz & Valente, 2017 |journal=PLOS ONE |volume=18 |issue=8 |article-number=e0289370 |doi=10.1371/journal.pone.0289370 |pmid=37552704 |pmc=10409265 |doi-access=free |name-list-style=amp }}</ref><ref>{{cite web |title=order Uropygi {{small|(Thorell, 1883)}} |website=BioLib |url=https://www.biolib.cz/en/taxon/id16785 |access-date=2023-03-10}}</ref> or Uropygi ''sensu lato''. The table below summarizes the two usages. When the qualifications ''s.l.'' and ''s.s.'' are omitted, the names Uropygi and Thelyphonida are ambiguous.

{| class="wikitable" |+ Alternative nomenclature |- !English names !! System 1<ref name=Clou17/> !! System 2<ref name=RuizVale17/> !! Recent families |- | || Clade Thelyphonida (Thelyphonida ''s.l.'') || Clade Uropygi (Uropygi ''s.l.'') || |- | whip scorpions ||Uropygi ''s.s.'' ||Thelyphonida ''s.s.'' || Thelyphonidae |- | short-tailed whip scorpions ||Schizomida ||Schizomida || Hubbardiidae, Protoschizomidae |}

Phylogenetic studies show the three groups, Amblypygi, Uropygi ''s.s.'' and Schizomida, to be closely related.<ref name=Garw>{{cite journal |title=Three-dimensional reconstruction and the phylogeny of extinct chelicerate orders |first1=Russell J. |last1=Garwood |first2=Jason A. |last2=Dunlop |date=2014 |journal=PeerJ |volume=2 |article-number=e641 |doi=10.7717/peerj.641 |pmid=25405073 |pmc=4232842 |doi-access=free }}</ref><ref name=Shul07>{{cite journal |first=Jeffrey W. |last=Shultz |year=2007 |title=A phylogenetic analysis of the arachnid orders based on morphological characters |journal=Zoological Journal of the Linnean Society |volume=150 |issue=2 |pages=221–265 |doi=10.1111/j.1096-3642.2007.00284.x|doi-access=free }}</ref> The Uropygi ''s.s.'' and Schizomida likely diverged in the late Carboniferous, somewhere in the tropics of Pangaea.<ref name=Clou17>{{Cite journal |last1=Clouse |first1=Ronald M. |last2=Branstetter |first2=Michael G. |last3=Buenavente |first3=Perry |last4=Crowley |first4=Louise M. |last5=Czekanski-Moir |first5=Jesse |last6=General |first6=David Emmanuel M. |last7=Giribet |first7=Gonzalo |last8=Harvey |first8=Mark S. |last9=Janies |first9=Daniel A. |display-authors=6 |year=2017 |title=First global molecular phylogeny and biogeographical analysis of two arachnid orders (Schizomida and Uropygi) supports a tropical Pangean origin and mid-Cretaceous diversification |journal=Journal of Biogeography |volume=44 |issue=11 |pages=2660–2672 |doi=10.1111/jbi.13076 |bibcode=2017JBiog..44.2660C |doi-access= |issn=1365-2699 |language=en}}</ref> {{clade |style=line-height:100% |label1={{nobr|&emsp; Pedipalpi &emsp;}} |1={{clade |1={{clade  |label1={{nobr|&emsp; Amblypygi &emsp;}} |1=whip spiders 120px }} |2={{clade |label1={{nobr|&emsp; Thelyphonida ''s.l.'' &emsp;}} |sublabel1=(Uropygi ''s.l.'') |1={{clade |label1=Uropygi ''s.s.'' |sublabel1={{nobr|&emsp; (Thelyphonida ''s.s.'') &emsp;}} |1=whip scorpions 80px |label2={{nobr|&emsp; Schizomida &emsp;}} |2=short-tailed whip scorpions 80px }} }} }} }}

==Description== Whip scorpions range from {{convert|25|to|85|mm|1|abbr=on}} in length, with most species having a body no longer than {{convert|30|mm|abbr=on}}; the largest species, of the genus ''Mastigoproctus'', can reach {{convert|85|mm|abbr=on}}.<ref name=schmidt93>{{cite book |author=Schmidt, Günther |year=1993 |title=Giftige und gefährliche Spinnentiere |language=de |trans-title=Poisonous and dangerous arachnids |publisher=Westarp Wissenschaften |isbn=978-3-89432-405-6}}</ref> An extinct ''Mesoproctus'' from the Lower Cretaceous Crato Formation could be the same size.<ref>{{cite journal |first1=Jason A. |last1=Dunlop |first2=David M. |last2=Martill |year=2002 |title=The first whipspider (Arachnida: Amblypygi) and three new whipscorpions (Arachnida: Thelyphonida) from the Lower Cretaceous Crato Formation of Brazil |journal=Transactions of the Royal Society of Edinburgh: Earth Sciences |volume=92 |issue=3 |pages=325–334 |doi=10.1017/S0263593300000262 |s2cid=140573577 |url=https://d-nb.info/1216876800/34 |format=PDF}}</ref> Because of their legs, claws, and "whip", though, they can appear much larger, and the heaviest specimen weighed was 12.4 grams (0.44 oz).<ref>{{cite book |last=Glenday |first=Craig |year=2013 |title=Guinness World Records 2014 |isbn=978-1-908843-15-9 |pages=[https://archive.org/details/guinnessworldrec0000unse_r3e7/page/33 33] |publisher=Guinness World Records Limited |url=https://archive.org/details/guinnessworldrec0000unse_r3e7/page/33}}</ref>

The opisthosoma consists of 12 segments. The first segment forms a pedicel, and each of the next eight segments has dorsal tergites. The last three segments are fused into closed rings, forming a pygidium that ends with a flagellum of 30–40 units.<ref>{{cite book |editor1=Minelli, Alessandro |editor2=Contrafatto, Giancarlo |date=10 Nov 2009 |title=Biological Science Fundamentals and Systematics |volume=III |page=225 |place=Oxford, UK |publisher=EOLSS Publications |series=Encyclopedia of Life Support Systems |isbn=978-1-84826-990-3 |url=https://books.google.com/books?id=8ZnEDAAAQBAJ&dq=Uropygi+pedicel+abdomen&pg=PA225 |via=Google Books}}</ref><ref>{{cite book |author=Ax, Peter |year=2000 |edition=English |orig-date=1999 original German ed. |title=Multicellular Animals: The phylogenetic system of the metazoa |volume=II: The Phylogenetic System of the Metazoa |page=103 |translator=Kiney, S. |publisher=Springer |isbn=978-3-642-08681-6 |doi=10.1007/978-3-662-10396-8 |s2cid=28516278 |url=https://books.google.com/books?id=x7vtCAAAQBAJ&dq=%22Only+the+last+three+segments+form+closed+rings%22&pg=PA103 |via=Google Books}}</ref>

Like the related orders Schizomida and Amblypygi, whip scorpions use only six legs for walking, with the first two legs serving as antennae-like sensory organs. All species also have very large scorpion-like pedipalps (pincers) but there is an additional large spine on each palpal tibia. They have one pair of median eyes at the front of the cephalothorax and up till five pairs of lateral eyes on each side of the head, a pattern also found in scorpions.<ref>{{cite conference |author=Weygoldt, Peter |date=1–5 July 1996 |title=Evolution and systematics of the Chelicerata |editor1=Bruin, J. Leo |editor2=van der Geest, P.S. |editor3=Sabelis, M.W. |book-title=Ecology and Evolution of the Acari |publication-date=1999 |pages=1–5, esp. p 5 |conference=3rd Symposium of the European Association of Acarologists |place=Amsterdam, NL |isbn=978-90-481-5200-1 |doi=10.1007/978-94-017-1343-6 |url=https://books.google.com/books?id=gcX0CAAAQBAJ&dq=%22Whip+scorpions%22+five+pairs+lateral+eyes&pg=PA5 |via=Google Books|url-access=subscription }}</ref><ref>{{cite report |title=Invertebrates |first1=Richard C. |last1=Brusca |first2=Gary J. |last2=Brusca |page=505 |website=juristas.com.br |url=https://juristas.com.br/wp-content/uploads/pdf-results/juristas-5aa181ee19460.pdf}}</ref> Whip scorpions have no venom glands, but they have glands near the rear of their abdomen that can spray a combination of acetic acid and caprylic acid when they are bothered.<ref name=schmidt93/> The acetic acid gives this spray a vinegar-like smell, giving rise to the common name ''vinegaroon''.

==Behaviour==

[[File:Vinegaroon - Mastigoproctus giganteus with Slate Millipede.jpg|thumb|''Mastigoproctus giganteus'', a predator of millipedes]] Whip scorpions are carnivorous, nocturnal hunters feeding mostly on insects, millipedes, scorpions, and terrestrial isopods,<ref name=schmidt93/> but sometimes on worms and slugs. ''Mastigoproctus'' sometimes preys on small vertebrates.<ref name=schmidt93/> The prey is crushed between special teeth on the inside of the trochanters (the second segment of the "legs") of the front appendages.

Males secrete a spermatophore (a united mass of sperm), which is transferred to the female following courtship behaviour, in which the male holds the ends of the female's first legs in his chelicerae. The spermatophore is deposited on the ground and picked up by the female using her genital area. In some genera, the male then uses his pedipalps to push the spermatophore into her body.<ref name=RuppFoxBarn04p569/>

thumb|''Mastigoproctus giganteus'' female with eggs After a few months, the female will dig a large burrow and seal herself inside. Up to 40 eggs are extruded, within a membranous broodsac that preserves moisture and remains attached to the genital operculum and the fifth segment of the mother's ventral opisthosoma. The female refuses to eat and holds her opisthosoma in an upward arch so that the broodsac does not touch the ground for the next few months, as the eggs develop into postembryos. Appendages become visible.<ref name=McMonigle-2017>{{cite book |first=Orin |last=McMonigle |date=November 2017 |title=Whipscorpions and Whipspiders: Culturing gentle monsters |publisher=Elytra and Antenna |isbn = 978-0-9802401-2-2}}</ref>

The white young that hatch from the postembryos climb onto their mother's back and attach themselves there with special suckers. After the first moult, when they look like miniature adults but with bright red palps, they leave the burrow. The mother may live up to two more years. The young grow slowly, going through four moults in about four years before reaching adulthood. They live for up to another four years.<ref name=schmidt93/><ref name=McMonigle-2017/>

==Distribution and habitat== Whip scorpions are found in tropical and subtropical areas, excluding Europe and Australia. Also, only a single species is known from Africa: ''Etienneus africanus'', probably a Gondwana relict, endemic to Senegal, the Gambia and Guinea-Bissau.<ref>{{cite journal |author1=Huff, Jeremy C. |author2=Prendini, Lorenzo |year=2009 |title=On the African whip scorpion, ''Etienneus africanus'' {{small|(Hentschel, 1899)}} (Thelyphonida: Thelyphonidae), with a redescription based on new material from Guinea-Bissau and Senegal |journal=American Museum Novitates |issue=3658 |pages=1–16 |doi=10.1206/674.1 |hdl=2246/5981 |s2cid=59942800 |url=https://www.biodiversitylibrary.org/bibliography/169014 }}</ref>

They usually dig burrows with their pedipalps, to which they transport their prey.<ref name=schmidt93/> They may also burrow under logs, rotting wood, rocks, and other natural debris. They prefer humid, dark places and avoid light. ''Mastigoproctus giganteus'', the giant whip scorpion, is found in more arid areas, including Arizona and New Mexico.<ref>{{cite web |title=Giant whip scorpion ''Mastigoproctus giganteus giganteus'' {{small|(Lucas, 1835)}} |website=Featured Creatures |series=Institute of Food and Agricultural Sciences, Department of Entymology |publisher=University of Florida |url=http://entnemdept.ufl.edu/creatures/misc/misc/giant_whip_scorpion.htm |access-date=2016-08-01 }}</ref>

==Subtaxa== {{Main|List of Thelyphonidae species}} As of 2026, the ''World Uropygi Catalog'' accepted the following 18 extant genera, all placed in the family Thelyphonidae:<ref name="NMBE">{{cite web |year=2026 |title=World Uropygi Catalog |url=https://wac.nmbe.ch/order/uropygi/7 |access-date=15 February 2026 |publisher=Natural History Museum |place=Bern, CH}}</ref>

{{Div col|colwidth=24em}} * ''Etienneus'' Heurtault, 1984 * ''Ginosigma'' Speijer, 1936 * ''Glyptogluteus'' Rowland, 1973 * ''Hypoctonus'' Thorell, 1888 * ''Labochirus'' Pocock, 1894 * ''Mastigoproctus'' Pocock, 1894 * ''Mayacentrum'' Viquez & Armas, 2006 * ''Mimoscorpius'' Pocock, 1894 * ''Ravilops'' Víquez & Armas, 2005 * ''Sheylayongium'' Teruel, 2018 * ''Thelyphonellus'' Pocock, 1894 * ''Thelyphonoides'' Krehenwinkel, Curio, Tacud & Haupt, 2009 * ''Thelyphonus'' Latreille, 1802 * ''Typopeltis'' Pocock, 1894 * ''Uroproctus'' Pocock, 1894 * ''Valeriophonus'' Viquez & Armas, 2005 * ''Wounaan'' Botero-Trujillo, Moreno-González & Prendini, 2024 * ''Yekuana'' Botero-Trujillo, Moreno-González & Prendini, 2024{{div col end}}

In addition, nine extinct genera were accepted, two within the family Thelyphonidae:<ref name="NMBE"/> * †''Mesoproctus'' Dunlop, 1998 * †''Mesothelyphonus'' Cai & Huang, 2017 and seven unplaced as to family:<ref name="NMBE"/> * †''Burmathelyphonia'' Wunderlich, 2015 * †''Geralinura'' Scudder, 1884 * †''Inmontibusichnus'' Knecht, Benner, Dunlop & Renczkowski, 2023 * †''Parageralinura'' Tetlie & Dunlop, 2008 * †''Parilisthelyphonus'' Knecht, Benner, Dunlop & Renczkowski, 2023 * †''Proschizomus'' Dunlop & Horrocks, 1996 * †''Prothelyphonus'' Frič, 1904

==Notes== {{Notelist}}

==References== {{Reflist|32em|refs=

<ref name=Camb72> {{cite journal |last=Cambridge |first=O.P. |year=1872 |title=On a new family and genus and two new species of Thelyphonidea |journal=Annals and Magazine of Natural History |volume=10 |issue=60 |series=4 |pages=409–413 |doi=10.1080/00222937208696729 |url=https://www.biodiversitylibrary.org/page/25172652 |access-date=2016-04-03}} </ref>

<ref name=Harv02> {{cite journal |first=M.S. |last=Harvey |year=2002 |title=The neglected cousins: What do we know about the smaller arachnid orders? |journal=Journal of Arachnology |volume=30 |issue=2 |pages=357–372 |doi=10.1636/0161-8202(2002)030[0357:TNCWDW]2.0.CO;2 |s2cid=59047074 |url=http://www.americanarachnology.org/JoA_Congress/JoA_v30_n2/arac-30-02-357.pdf |archive-url=https://web.archive.org/web/20120207165733/http://www.americanarachnology.org/JoA_Congress/JoA_v30_n2/arac-30-02-357.pdf |archive-date=2012-02-07}} </ref>

<ref name=Latr02> {{cite book |last=Latreille |first=Pierre A. |year=1802 |contribution=Genre Thélyphone |title=Histoire naturelle générale et particulière des Crustacés et des Insectes |volume=3 |publisher=Dufart |location=Paris, FR |page=47 |contribution-url=https://www.biodiversitylibrary.org/page/24884903 |language=fr }} </ref>

<ref name=Latr04> {{cite book |last=Latreille |first=Pierre A. |year=1804 |contribution=Genre Thélyphone |title=Histoire naturelle générale et particulière des Crustacés et des Insectes |volume=7 |publisher=Dufart |location=Paris, FR |pages=130–132 |contribution-url=https://www.biodiversitylibrary.org/page/24883087 |language=fr }} </ref>

<ref name=RuppFoxBarn04p569> {{cite book |last1=Ruppert |first1=E.E. |first2=R.S. |last2=Fox |first3=R.D. |last3=Barnes |name-list-style=amp |year=2004 |title=Invertebrate Zoology |publisher=Brooks/Cole |edition=7th |isbn=978-0-03-025982-1 |pages=[https://archive.org/details/isbn_9780030259821/page/569 569–570] |url-access=registration |url=https://archive.org/details/isbn_9780030259821/page/569 }} </ref>

}}

==External links== {{Commons category|Thelyphonida}}

Category:Uropygi Category:Arachnid orders Category:Extant Pennsylvanian first appearances Category:Carboniferous arachnids Category:Permian arachnids Category:Mesozoic arachnids Category:Cenozoic arachnids Category:Taxa named by Tamerlan Thorell