The Dionycha are a clade of spiders (

Araneomorphae The Araneomorphae (also called the Labidognatha) are an infraorder of spiders. They are distinguishable by chelicerae (fangs) that point diagonally forward and cross in a pinching action, in contrast to the Mygalomorphae (tarantulas and their ...

Entelegynae The Entelegynae or entelegynes are a subgroup of araneomorph spiders, the largest of the two main groups into which the araneomorphs were traditionally divided. Females have a genital plate ( epigynum) and a "flow through" fertilization system; m ...

), characterized by the possession of two tarsal claws with tufts of hairs (setae) beside them, which produce strong adhesion, enabling some species to climb glass. The

circumscription Circumscription may refer to: *Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) *Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...

of the group has varied widely; a 2021 analysis resulted in about 20 families, including

Salticidae Jumping spiders are a group of spiders that constitute the family Salticidae. As of 2019, this family contained over 600 described genera and over 6,000 described species, making it the largest family of spiders at 13% of all species. Jumping spi ...

(jumping spiders),

Gnaphosidae Ground spiders comprise Gnaphosidae, the seventh largest spider family with over 2,000 described species in over 100 genera distributed worldwide. There are 105 species known to central Europe, and common genera include ''Gnaphosa'', ''Drassode ...

(ground spiders), and

Clubionidae The sac spiders of the family Clubionidae have a very confusing taxonomic history. Once, this family was a large catch-all taxon for a disparate collection of spiders, similar only in that they had eight eyes arranged in two rows and conical anter ...

. The Dionycha are considered to be a subgroup of the larger

RTA clade The RTA clade is a clade of araneomorph spiders, united by the possession of a retrolateral tibial apophysis – a backward-facing projection on the tibia of the male pedipalp. The clade contains over 21,000 species, almost half the current total ...

. Most species hunt their prey instead of building webs. There are no

cribellate Cribellum literally means "little sieve", and in biology the term generally applies to anatomical structures in the form of tiny perforated plates. In certain groups of diatoms it refers to microscopically punctured regions of the frustule, or o ...

members in the Dionycha.Griswold ''et al.'' 1999 Today it is thought that the reduction of the third claw present in ancestral spiders evolved several times independently, so this alone is not a criterion that defines the clade.

Families

In 2021, a group of several spider taxonomists published a major study of the phylogeny of Dionycha, using genetic and phenotypic data. It included the families listed below: ;Dionycha * Prodidomidae *Dionycha A clade ** Trachycosmidae **

Anyphaenidae Anyphaenidae is a family of araneomorph spiders, sometimes called anyphaenid sac spiders. They are distinguished from the sac spiders of the family Clubionidae and other spiders by having the abdominal spiracle placed one third to one half of th ...

** Phrurolithidae ** Trachelidae **

Liocranidae Liocranidae is a family of araneomorph spiders first described by Eugène Simon in 1897. They are one of several groups called "sac spiders". The holarctic genus '' Agroeca'' is the best-known, but it also includes various genera of more obscure ...

Gallieniellidae Gallieniellidae is a family of spiders first described by J. Millot in 1947. It was originally thought to be endemic (ecology), endemic to Madagascar until species were also found in southern Kenya, northeastern Argentina, and Australia. ''Drassod ...

Cithaeronidae Cithaeronidae is a small family of araneomorph spiders first described by Simon in 1893 Female ''Cithaeron'' are about long, males about . They are pale yellowish, fast-moving spiders that actively hunt at night and rest during the day, building ...

** Trochanteriidae **

(including former

Ammoxenidae Ground spiders comprise Gnaphosidae, the seventh largest spider family with over 2,000 described species in over 100 genera distributed worldwide. There are 105 species known to central Europe, and common genera include '' Gnaphosa'', '' Drassode ...

) **

Lamponidae Lamponidae is a family of spiders first described by Eugène Simon in 1893. It contains about 200 described species in 23 genera, most of which are endemic to Australia, with the genus ''Centrocalia'' endemic to New Caledonia, and two ''Lampona ...

*Dionycha B clade **

Philodromidae Philodromidae, also known as philodromid crab spiders and running crab spiders, is a family of araneomorph spiders first described by Tord Tamerlan Teodor Thorell in 1870 (then known as subfamily Philodrominae within Thomisidae). It contains over ...

Xenoctenidae Xenoctenidae is a family of araneomorph spiders separated from Miturgidae in 2017. Genera and species , the World Spider Catalog accepts the following genera and species: Incasoctenus Mello-Leitão, 1942 *'' Incasoctenus perplexus'' Mello-Leit ...

Miturgidae Miturgidae is a family of araneomorph spiders that includes nearly 170 species in 29 genera worldwide. First described by Eugène Simon in 1886, it has been substantially revised, and includes the previous family Zoridae as a synonym, and exclud ...

** Cheiracanthiidae **

Selenopidae Selenopidae, also called wall crab spiders, wall spiders and flatties, is a family of araneomorph spiders first described by Eugène Simon in 1897. It contains over 280 species in nine genera, of which '' Selenops'' is the most well-known. This fa ...

** Viridasiidae **

Corinnidae Corinnidae is a family of araneomorph spiders, sometimes called corinnid sac spiders. The family, like other "clubionoid" families, has a confusing taxonomic history. Once it was a part of the large catch-all taxon Clubionidae, now very much small ...

Families

Footnotes

References

External links