Bipectina

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Bipectina
Dipluridae - Diplura fasciata.JPG
Diplura lineata , a member of the family Dipluridae
PSM V38 D203 Section view of the curved burrow of stothis astuta.jpg
Burrow of Trichopelma astuta , a member of the family Theraphosidae
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Mygalomorphae
Clade: Avicularioidea
Clade: Bipectina
Goloboff, 1993 [1]
Families

See text.

Bipectina is a clade of avicularioid mygalomorph spiders first proposed by Pablo A. Goloboff in 1993, based on a morphological cladistic analysis. The clade was marked by a number of morphological features, and in particular by the presence of two rows of teeth on the superior tarsal claws of the legs of both sexes, meaning that the claws were bipectinate. [1] The clade was supported by some subsequent analyses, although not all. [2] [3] A major phylogenetic study in 2020 upheld the monophyly of the clade, which contained 19 of the 25 accepted families of the Avicularioidea. [4]

Contents

The majority of extant members of the Bipectina clade live in a burrow with one or more trapdoors, many adding radial alarm threads that alert them to the presence of prey. Others have reverted to using various kinds of web, as the earliest avicularioids are believed to have done, or have lost trapdoors, living in open burrows. [4]

Taxonomy

The clade Bipectina was first proposed by Pablo A. Goloboff in 1993, based on a purely morphological cladistic analysis. One feature used in defining the clade was the bipectinate superior tarsal claws of the legs of both sexes (i.e. the claws had two rows of teeth). Females in the clade also had pedipalps in which their usual single rows of teeth were markedly displaced to the prolateral side of the claw. [1] The clade was supported by most subsequent analyses, including those that included molecular evidence, although with different family compositions. [2] [3] [5]

Phylogeny

The preferred cladogram from a 2020 phylogenetic study of the Mygalomorphae is shown below. Bipectina was resolved as a derived clade containing the majority of families of the Avicularioidea (19 out of 25). Some nodes within the clade had lower support (marked ♦ below), but the clade as a whole was well supported. [4]

Avicularioidea

Basal families (6)

Bipectina

Paratropididae

Stasimopidae

Venom Clade

Atracidae

Actinopodidae

Domiothelina

Halonoproctidae

Migidae

Idiopidae

Ctenizidae

Euctenizidae

Crassitarsae  
Theraphosoidina

Bemmeridae

Barychelidae

Theraphosidae

"Nemesioidina"

Nemesiidae

Pycnothelidae

Dipluridae

Cyrtaucheniidae

Anamidae

Entypesidae

Microstigmatidae

Bipectina is estimated to have diverged from its sister (the small family Macrothelidae) around 179–162  Ma (roughly the middle of the Jurassic), possibly in Africa. The ancestor of the Avicularioidea probably used a sheet web to aid in prey capture. The status of the ancestor of Bipectina is not entirely clear, but the majority of current members of the Bipectina clade have a burrow with one or more trapdoors and radial alarm threads. Trapdoors have been shown to reduce foraging efficiency, but may serve as protection from predators or adverse environmental factors. Reduced selection pressure may explain why some members of the clade have lost trapdoors. Others have reverted to using some form of web in prey capture. [4]

Families

According to Opatova et al. (2020), the clade includes the following families, some of which were first described at this rank in their study: [4]

Related Research Articles

<span class="mw-page-title-main">Mygalomorphae</span> Infraorder of arachnids (spiders)

The Mygalomorphae, or mygalomorphs, are an infraorder of spiders, and comprise one of three major groups of living spiders with over 3000 species, found on all continents except Antarctica. Many members are known as trapdoor spiders due to them forming trapdoors over their burrows. Other prominent groups include Australian funnel web spiders and tarantulas, with the latter accounting for around one third of all mygalomorphs.

<span class="mw-page-title-main">Ctenizidae</span> Family of spiders

Ctenizidae is a small family of mygalomorph spiders that construct burrows with a cork-like trapdoor made of soil, vegetation, and silk. They may be called trapdoor spiders, as are other, similar species, such as those of the families Liphistiidae, Barychelidae, and Cyrtaucheniidae, and some species in the Idiopidae and Nemesiidae. The name comes from the distinctive behavior of the spiders to construct trapdoors, and ambush prey from beneath them.

<span class="mw-page-title-main">Hexathelidae</span> Family of spiders

Hexathelidae is a family of mygalomorph spiders. It is one of a number of families and genera of spiders known as funnel-web spiders. In 2018, the family was substantially reduced in size by genera being moved to three separate families: Atracidae, Macrothelidae and Porrhothelidae. Atracidae includes the most venomous species formerly placed in Hexathelidae.

<span class="mw-page-title-main">Nemesiidae</span> Family of spiders

Nemesiidae, also known as funnel-web trapdoor spiders, is a family of mygalomorph spiders first described by Eugène Simon in 1889, and raised to family status in 1985. Before becoming its own family, it was considered part of "Dipluridae".

<span class="mw-page-title-main">Dionycha</span> Clade of spiders

The Dionycha are a clade of spiders (Araneomorphae:Entelegynae), 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 of the group has varied widely; a 2021 analysis resulted in about 20 families, including Salticidae, Gnaphosidae, and Clubionidae.

<span class="mw-page-title-main">Atypoidea</span> Superfamily of arachnids

Atypoidea is a clade of mygalomorph spiders, one of the two main groups into which the mygalomorphs are divided. It has been treated at the rank of superfamily. It contains five families of spiders:

<span class="mw-page-title-main">Euctenizidae</span> Family of spiders

The Euctenizidae are a family of mygalomorph spiders. They are now considered to be more closely related to Idiopidae.

<i>Eucteniza</i> Genus of spiders

Eucteniza is a genus of trapdoor spiders in the family Euctenizidae containing at least 14 species occurring in Mexico and the southern United States. Species are distinguished by a softened rear portion of the carapace, and males possess large spines on the first two pairs of walking legs that are used to hold females during mating. Like other trapdoor spiders they create burrows with a hinged lid, from which they await passing insects and other arthropods to prey upon. Many species are known from only one or two localities, or from only male specimens. More species are expected to be discovered. Eucteniza is closely related to spiders of the genera Entychides and Neoapachella.

Rosamygale is a genus of extinct Triassic spiders, with a single described species, Rosamygale grauvogeli. It is the oldest known member of the Mygalomorphae, one of the three main divisions of spiders, which includes well known forms such as tarantulas and Australian funnel-web spiders. It was described by Selden and Gall in 1992, from specimens found in the Middle Triassic aged Gres a Meules and Grès à Voltzia geological formations in France. It is also considered to be the oldest known member of the Avicularioidea, one of the two main divisions of Mygalomorphae.

Stenoterommata is a genus of South American araneomorph spiders in the family Pycnothelidae. It was first described by E. L. Holmberg in 1881. Originally placed with the Ctenizidae, it was transferred to the funnel-web trapdoor spiders in 1985, then to the Pycnothelidae in 2020. It is a senior synonym of Ctenochelus.

Pionothele is a genus of African mygalomorph spiders in the family Pycnothelidae. It was first described by William Frederick Purcell in 1902. As of June 2020 it contains 2 species, found in Namibia and South Africa: P. gobabeb, and P. straminea. Originally placed with the Ctenizidae, it was transferred to the funnel-web trapdoor spiders in 1985, then to the Pycnothelidae in 2020.

<span class="mw-page-title-main">Halonoproctidae</span> Family of spiders

Halonoproctidae is a family of mygalomorph spiders, split off from the family Ctenizidae in 2018. Species in the family are widely distributed in North and Central America, Australasia, Asia, southern Europe and North Africa. One species is recorded from Venezuela in South America. They are relatively large, sombrely coloured spiders, that live in burrows with some kind of trapdoor.

<span class="mw-page-title-main">Avicularioidea</span> Clade of spiders

Avicularioidea is a clade of mygalomorph spiders, one of the two main clades into which mygalomorphs are divided. It has been treated at the rank of superfamily.

<span class="mw-page-title-main">Anamidae</span> Family of spiders

Anamidae is a family of Australian mygalomorph spiders. It was first described as a tribe by Simon in 1889, then raised to the subfamily Anaminae of the family Nemesiidae, before being raised to a family level by Opatova et al. in 2020.

Pycnothelidae is a family of mygalomorph spiders first described in 1917. It was downgraded to a subfamily of the funnel-web trapdoor spiders in 1985, but returned to family status in 2020.

Euagridae is a family of mygalomorph spiders. The group was first described as a tribe in 1979 by Robert Raven, who in 1985 elevated it to a subfamily. In 2020, Optova et al. elevated it further to a family.

<span class="mw-page-title-main">Domiothelina</span> Clade of spiders

Domiothelina is a clade of avicularioid mygalomorph spiders first proposed by Robert J. Raven in 1985, based on a morphological cladistic analysis. Raven characterized the clade by a number of shared features, including the domed apical segment of the posterior lateral spinnerets. The clade has been supported to some degree by subsequent molecular analyses, although with a somewhat different composition.

<span class="mw-page-title-main">Crassitarsae</span> Clade of spiders

Crassitarsae is a clade of avicularioid mygalomorph spiders first proposed by Robert J. Raven in 1985, based on a morphological cladistic analysis. Raven characterized the clade by a number of shared features, including the presence of some scopulae on the tarsi. The clade has been supported to some degree by subsequent molecular analyses, although with a somewhat different composition.

<span class="mw-page-title-main">Theraphosoidina</span> Clade of spiders

Theraphosoidina is a clade of avicularioid mygalomorph spiders first proposed by Robert J. Raven in 1985, based on a morphological cladistic analysis. Raven included three families: Theraphosidae, Paratropididae and Barychelidae. Subsequent molecular phylogenetic studies upheld the relationship between the Theraphosidae and Barychelidae, but found that Paratropidae fell outside the clade.

<span class="mw-page-title-main">Nemesioidina</span> Clade of spiders

Nemesioidina is a clade of avicularioid mygalomorph spiders proposed in 2020, based on a molecular phylogenetic analysis.

References

  1. 1 2 3 Goloboff, Pablo A. (1993), "A Reanalysis of Mygalomorph Spider Families (Araneae)", American Museum Novitates (3056), hdl:2246/5017 , retrieved 2020-07-20
  2. 1 2 Hedin, Marshal & Bond, Jason E. (2006), "Molecular phylogenetics of the spider infraorder Mygalomorphae using nuclear rRNA genes (18S and 28S): Conflict and agreement with the current system of classification", Molecular Phylogenetics and Evolution, 41 (2): 454–471, doi:10.1016/j.ympev.2006.05.017, PMID   16815045
  3. 1 2 Bond, Jason E.; Hendrixson, Brent E.; Hamilton, Chris A. & Hedin, Marshal (2012), "A Reconsideration of the Classification of the Spider Infraorder Mygalomorphae (Arachnida: Araneae) Based on Three Nuclear Genes and Morphology", PLOS ONE, 7 (6): e38753, doi: 10.1371/journal.pone.0038753 , PMC   3378619 , PMID   22723885
  4. 1 2 3 4 5 Opatova, Vera; Hamilton, Chris A.; Hedin, Marshal; Montes De Oca, Lauren; Král, Jiři; Bond, Jason E. (2019), "Phylogenetic Systematics and Evolution of the Spider Infraorder Mygalomorphae Using Genomic Scale Data", Systematic Biology, 69 (4): 671–707, doi: 10.1093/sysbio/syz064 , PMID   31841157
  5. Bond, Jason E.; Garrison, Nicole L.; Hamilton, Chris A.; Godwin, Rebecca L.; Hedin, Marshal & Agnarsson, Ingi (2014), "Phylogenomics Resolves a Spider Backbone Phylogeny and Rejects a Prevailing Paradigm for Orb Web Evolution", Current Biology, 24 (15): 1765–1771, doi: 10.1016/j.cub.2014.06.034 , PMID   25042592