Plutonium_zwierleini_-_Trecastagni_-_1_-_Lucio_Bonato

Forcipules are the modified, pincer-like, front legs of

centipede Centipedes (from Neo-Latin , "hundred", and Latin , "foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', "lip", and Neo-Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, ...

s that are used to inject

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

into prey. They are the only known examples of front legs acting as venom injectors.

Nomenclature

Forcipules go by a variety of names in both scientific and colloquial usages. They are sometimes known as poison claws or jaw legs, 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). In the specific case in which the forcipules are used to inject venom, they are called toxicognaths (from ''toxic'' + the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

'' gnathos'', jaw). The term forcipule references their similarity with

forceps Forceps (: forceps or considered a plural noun without a singular, often a pair of forceps; the Latin plural ''forcipes'' is no longer recorded in most dictionaries) are a handheld, hinged instrument used for grasping and holding objects. Forcep ...

Anatomy, systematics, and variation

Forcipules evolved from the maxillipeds – front legs – of centipedes'

last common ancestor A most recent common ancestor (MRCA), also known as a last common ancestor (LCA), is the most recent individual from which all organisms of a set are inferred to have descended. The most recent common ancestor of a higher taxon is generally assu ...

, 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.

References

{{Arthropod-anatomy-stub Myriapod anatomy