| Nemesioidina | |
|---|---|
 | |
| Calisoga sp., a member of the family Nemesiidae | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Class: | Arachnida |
| Order: | Araneae |
| Infraorder: | Mygalomorphae |
| Clade: | Crassitarsae |
| Clade: | Nemesioidina |
| Families | |
Nemesioidina is a clade of avicularioid mygalomorph spiders proposed in 2020, based on a molecular phylogenetic analysis. [1]
The clade was identified in a major 2020 phylogenetic study of the Mygalomorphae. The paper in which the study was published uses double-quotes around the name, for reasons that are not explained. [1] In the preferred cladogram, Nemesioidina is sister to Theraphosoidina, treated as clade, [1] but formally named and given a rank by Robert Raven in 1985, [2] whereas Nemesioidina was not formally named. [1] As traditionally circumscribed, the family Nemesiidae and others apparently related to it, particularly Cyrtaucheniidae and Dipluridae, were known not to be monophyletic, with the Cyrtaucheniidae probably representing at least four different and unrelated lineages. [3] Opatova et al. suggest that because of its improved sampling and high support values, their 2020 study "brings long-needed insight and resolution to the 'nemesiid' problem". They re-circumscribed families and created new ones by elevating sub-family taxa to family rank. The resulting families were monophyletic (although some genera remain unsampled), as was the Nemesioidina as a whole. [1]
An outline version of the preferred cladogram from a 2020 phylogenetic study of the Mygalomorphae is shown below. (A node with lower support is marked ♦.) [1]
| Avicularioidea |
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The earliest ancestor of the Nemesioidina is estimated to have diverged around 125 Ma (early to middle Cretaceous). It probably lived in a burrow with a trapdoor, as did ancestral members of the Crassitarsae. However, the trapdoor has been lost or replaced by a turret or collar around the entrance in some members of the Nemesiidae, Pycnothelidae and Anamidae. Trapdoors have been shown to reduce foraging efficiency, but may serve as protection from predators or adverse environmental factors, so that their loss may be explained by reduced selection pressure. Some diplurids have regained the even more ancestral condition of catching prey in a sheet-like web. [1]
According to Opatova et al. (2020), the clade includes the following families, three of which (Anamidae, Entypesidae and Pycnothelidae) were formerly treated within Nemesiidae, and were elevated to families as a result of the study: [1]
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.
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.
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".
Stanwellia is a genus of South Pacific mygalomorph spiders in the family Pycnothelidae. It was first described by W. J. Rainbow & R. H. Pulleine in 1918. Originally placed with the curtain-web spiders, it was transferred to the funnel-web trapdoor spiders in 1985, then to the Pycnothelidae in 2020. It is a senior synonym of Aparua.
The Euctenizidae are a family of mygalomorph spiders. They are now considered to be more closely related to Idiopidae.
Acanthogonatus is a genus of South American mygalomorph spiders in the family Pycnothelidae. It was first described by Ferdinand Anton Franz Karsch in 1880. Originally placed with the brushed trapdoor spiders, it was transferred to the funnel-web trapdoor spiders in 1985, then to the Pycnothelidae in 2020.
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.
Entypesa is a genus of African mygalomorph spiders in the family Entypesidae. It was first described by Eugène Louis Simon in 1902. Originally placed with the curtain-web spiders, it was transferred to the funnel-web trapdoor spiders in 1985, then to the Entypesidae in 2020. It is a senior synonym of Pseudohermacha.
Hermacha is a genus of mygalomorphae spiders in the family Entypesidae. It was first described by Eugène Louis Simon in 1889. Originally placed with the Ctenizidae, it was transferred to the funnel-web trapdoor spiders in 1985, then to the Entypesidae in 2020. It is a senior synonym of Damarchodes and Hermachola.
Kwonkan is a genus of Australian tarantulas first described by Barbara York Main in 1983. It was originally assigned to Dipluridae, but was later assigned to Nemesiidae due to similarities to the genus Aname, before being transferred to the family Anamidae in 2010. Yilgarnia is now considered a synonym for this genus, and its type species is assigned to Kwonkan currycomboides.
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.
Pycnothele is a genus of South American mygalomorph spiders in the family Pycnothelidae. First described by Ralph Vary Chamberlin in 1917, it was moved to the funnel-web trapdoor spiders in 1985, but moved back to Pycnothelidae in 2020. It is a senior synonym of Agersborgia and Androthelopsis.
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.
Bayana labordai is a species of South American mygalomorph spiders in the family Pycnothelidae. It is the only species in the monotypic genus Bayana. It was first described by F. Pérez-Miles, F. G. Costa & L. Montes de Oca in 2014, and is found in Uruguay and Brazil. Originally placed with the funnel-web trapdoor spiders, it was transferred to the Pycnothelidae in 2020.
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.
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. The clade was supported by some subsequent analyses, although not all. A major phylogenetic study in 2020 upheld the monophyly of the clade, which contained 19 of the 25 accepted families of the Avicularioidea.
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.
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.
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.