Araneoidea is a

taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

araneomorph 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 ...

spiders, termed "araneoids", treated as a superfamily. As with many such groups, its

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 ...

has varied; in particular some families that had at one time moved to the

Palpimanoidea The Palpimanoidea or palpimanoids, also known as assassin spiders, are a group of araneomorph spiders, originally treated as a superfamily. As with many such groups, its circumscription has varied. , the following five families were included: * A ...

have more recently been restored to Araneoidea. A 2014 treatment includes 18 families, with the araneoids making up about 26% of the total number of known spider

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

; a 2016 treatment includes essentially the same taxa, but now divided into 17 families.

Taxonomy

Many of the differences in circumscription concern the relationship between Araneoidea and

. In 1984, Raymond R. Forster and Norman I. Platnick proposed that some groups previously considered araneoid actually belonged in the distantly related Palpimanoidea, including the families Holarchaeidae, Micropholcommatidae, Mimetidae and Pararchaeidae. Subsequent phylogenetic studies have rejected this proposal, firmly placing these four families in Araneoidea (some included in other families).

Phylogeny

Although there is an increasing consensus on the

of Araneoidea, the relationship between many of its families remains uncertain. In 2014, Hormiga and Griswold produced the summary

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

shown below, based on what they considered to be the nine most comprehensive phylogenetic studies of Araneoidea prior to their article. Polytomies in the cladogram represent either conflicting results from the different studies or the absence of sufficiently comprehensive studies. A subsequent study by Dimitrov et al. in 2016 produced more resolved cladograms; their maximum likelihood cladogram based on the analysis of their entire dataset is shown below. Some of their other analyses produced different results; for example, a Bayesian analysis produced a monophyletic Anapidae rather than splitting it into two clades. They concluded that "the amount of information available to resolve these families is limited, particularly at the interfamilial and deeper levels. Only some of the interfamilial groupings ... were recovered with high support." One clade which is well supported is (Mimetidae + (Arkyidae + Tetragnathidae)). Both Hormiga and Griswold and Dimitrov et al. conclude that the sister taxon of Araneoidea is Nicodamidae

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(which Dimitrov et al. split into two families and call Nicodamoidea). It is likely that relationships will change further when more studies are carried out, since "currently available molecular and morphological data are insufficient to robustly resolve relationships".

Included families

After Dimitrov et al. 2016 *

Anapidae Anapidae is a family of rather small spiders with 231 described species in 58 genera. It includes the former family Micropholcommatidae as the subfamily Micropholcommatinae, and the former family Holarchaeidae. Most species are less than long. ...

Theridiidae Theridiidae, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders, is a large family of araneomorph spiders first described by Carl Jakob Sundevall in 1833. This diverse, globally distributed family includes over 3,000 sp ...

* Theridiosomatidae * Synotaxidae * Araneidae *

Nesticidae Scaffold web spiders (Nesticidae) is a family of araneomorph spiders closely allied with tangle web spiders. Like the " Theridiidae", these spiders have a comb of serrated bristles on the hind tarsi that are used to pull silk bands from the spin ...

* Synaphridae * Symphytognathidae *

Cyatholipidae Cyatholipidae is a family of spiders first described by Eugène Simon in 1894. Most live in moist montane forest, though several species, including '' Scharffia rossi'', live in dry savannah regions. They occur in Africa, including Madagascar, N ...

Physoglenidae Physoglenidae is a family of araneomorph spiders first described by Alexander Petrunkevitch in 1928 as a subfamily of Pholcidae. It was later moved to Synotaxidae until a study in 2016 showed that they formed a distinct clade. Genera , the Wor ...

Pimoidae Pimoidae is a small family of araneomorph spiders first described by J. Wunderlich in 1986. As re-circumscribed in 2021, it is monophyletic, and contained 85 species in two genera. It is closely related to the Linyphiidae, and is sometimes treat ...

Linyphiidae Linyphiidae, spiders commonly known as sheet weavers (from the shape of their webs), or money spiders (in the United Kingdom, Ireland, Australia, New Zealand, and in Portugal, from the superstition that if such a spider is seen running on you, ...

Mysmenidae Mysmenidae is a spider family with about 135 described species in thirteen genera. The family is one of the least well known of the orb-weaving spiders because of their small size () and cryptic behaviour. These spiders are found in humid habitats ...

Malkaridae Malkaridae is a small family of araneomorph spiders first described by Valerie Todd Davies in 1980. In 2017, the family Pararchaeidae was brought into synonymy with Malkaridae. Genera , the World Spider Catalog accepts the following genera: *'' ...

Mimetidae Pirate spiders, members of the family Mimetidae, are araneomorph spiders which typically feed on other spiders. The family Mimetidae contains roughly 200 species divided among 12 genera, of which ''Mimetus'' and ''Ero'' are the most common. Mim ...

Arkyidae Arkyidae is a family of araneomorph spiders first described by Ludwig Carl Christian Koch in 1872 as a subfamily of Araneidae, and later elevated to a full family in 2017. Genera and species This section lists all described species In bi ...

Tetragnathidae Long-jawed orb weavers or long jawed spiders (Tetragnathidae) are a family of araneomorph spiders first described by Anton Menge in 1866. They have elongated bodies, legs, and chelicerae, and build small orb webs with an open hub with few, wide-se ...

Extinct families

After Dunlop et al. 2013 and Magalhaes et al. 2020 *† Baltsuccinidae * † Burmascutidae * † Cretamysmenidae * † Juraraneidae * † Leviunguidae * † Praetheridiidae * † Protheridiidae * † Pumiliopimoidae * † Zarqaraneidae

References

{{Taxonbar, from=Q774956 Araneomorphae Arachnid superfamilies