forcipule
{{Short description|Appendage unique to centipedes}}
{{redirect|Poison claw|the poison claw sea urchin|Toxopneustes pileolus}}
Forcipules are the modified, pincer-like, front legs of centipedes that are used to inject venom into prey.{{Cite journal |last1=Dugon |first1=Michel M. |last2=Black |first2=Alexander |last3=Arthur |first3=Wallace |date=2012-05-01 |title=Variation and specialisation of the forcipular apparatus of centipedes (Arthropoda: Chilopoda): A comparative morphometric and microscopic investigation of an evolutionary novelty |url=https://www.sciencedirect.com/science/article/pii/S1467803912000151 |journal=Arthropod Structure & Development |volume=41 |issue=3 |pages=231–243 |doi=10.1016/j.asd.2012.02.001 |pmid=22370199 |issn=1467-8039}}{{Cite web |title=Are Centipedes Poisonous? {{!}} Do Centipedes Bite or Sting? {{!}} Orkin |url=https://www.orkin.com/pests/centipedes/which-centipedes-are-poisonous |access-date=2022-08-23 |website=www.orkin.com}} They are the only known examples of front legs acting as venom injectors.{{Cite journal |last=Shelley |first=Rowland M. |date=March 1999 |title=Centipedes and Millipedes with Emphasis on North American Fauna |url=https://sites.google.com/g.emporia.edu/ksn/ksn-home/vol-45-no-3-centipedes-and-millipedes-with-emphasis-on-n-america-fauna |journal=Kansas School Naturalist |volume=45 |issue=3 |pages=3–16 |citeseerx=10.1.1.365.8963 |archive-url=https://web.archive.org/web/20161112025334/http://www.emporia.edu/ksn/v45n3-march1999/ |archive-date=2016-11-12}}
Nomenclature
Forcipules go by a variety of names in both scientific and colloquial usages. They are sometimes known as poison claws or jaw legs,{{Cite web |title=Molecular Expressions: Science, Optics & You - Olympus MIC-D: Oblique Gallery - Centipede Poison Claws |url=https://micro.magnet.fsu.edu/optics/olympusmicd/galleries/oblique/centipedepoisonclaw.html |access-date=2022-09-05 |website=micro.magnet.fsu.edu}} referencing their evolution from maxillipeds, a term which they are also sometimes known by in the context of centipedes (maxillipeds, maxillipedes). Other names include prehensors, telopodites, and forcipulae (singular forcipula).{{Cite journal |last=Shelley |first=Rowland M |date=March 1999 |title=Centipedes and Millipedes with an emphasis on North American fauna |journal=The Kansas School Naturalist |volume=45 |issue=3 |pages=3–15 |doi= |issn=0022-877X |via=CiteSeerX}}{{Cite journal |last1=Bonato |first1=Lucio |last2=Edgecombe |first2=Gregory |last3=Lewis |first3=John |last4=Minelli |first4=Alessandro |last5=Pereira |first5=Luis |last6=Shelley |first6=Rowland |last7=Zapparoli |first7=Marzio |date=2010-11-18 |title=A common terminology for the external anatomy of centipedes (Chilopoda) |url=http://zookeys.pensoft.net/articles.php?id=2466 |journal=ZooKeys |issue=69 |pages=17–51 |doi=10.3897/zookeys.69.737 |pmid=21594038 |pmc=3088443 |issn=1313-2970|doi-access=free }} In the specific case in which the forcipules are used to inject venom, they are called toxicognaths (from toxic + the Greek gnathos, jaw).{{Cite web |title=Definition of TOXICOGNATH |url=https://www.merriam-webster.com/dictionary/toxicognath |access-date=2022-08-23 |website=www.merriam-webster.com |language=en}}
The term forcipule references their similarity with forceps.
Anatomy, systematics, and variation
File:Eupolybothrus_cavernicolus_forcipules.jpg (Lithobiidae)]]
Forcipules evolved from the maxillipeds – front legs – of centipedes' last common ancestor, believed to be somewhat Scutigeromorph-like. They were initially leg-like, then progressed into a more pincer or claw-like shape, as seen today, and restricted to horizontal movement. The forcipules of modern Scutigeromorphs are the most significantly different in shape: they are more leg-like, and cannot hold prey like they are used among other orders: they are used for envenomation only, making their use more comparable to a knife than a pincer.{{Citation |last=Dugon |first=Michel M. |title=Evolution, Morphology, and Development of the Centipede Venom System |date=2017 |url=http://link.springer.com/10.1007/978-94-007-6458-3_1 |work=Evolution of Venomous Animals and Their Toxins |series=Toxinology |pages=261–278 |editor-last=Malhotra |editor-first=Anita |place=Dordrecht |publisher=Springer Netherlands |doi=10.1007/978-94-007-6458-3_1 |isbn=978-94-007-6457-6 |access-date=2022-08-23}}
References
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