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 similar species, such as those of the families Liphistiidae, Barychelidae, and Cyrtaucheniidae, and some species in the Idiopidae and Nemesiidae. In 2018, the family Halonoproctidae was split off from the Ctenizidae, leaving only three genera; later, the genus Stasimopus was removed. The family now consists of only two genera and five species.
Spider taxonomy is that part of taxonomy that is concerned with the science of naming, defining and classifying all spiders, members of the Araneae order of the arthropod class Arachnida with about 46,000 described species. However, there are likely many species that have escaped the human eye to this day, and many specimens stored in collections waiting to be described and classified. It is estimated that only one third to one half of the total number of existing species have been described.
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".
The Haplogynae or haplogynes are one of the two main groups into which araneomorph spiders have traditionally been divided, the other being the Entelegynae. Morphological phylogenetic studies suggested that the Haplogynae formed a clade; more recent molecular phylogenetic studies refute this, although many of the ecribellate haplogynes do appear to form a clade, Synspermiata.
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:
The Aviculariinae are a subfamily of spiders in the family Theraphosidae (tarantulas). They can be distinguished from other theraphosids by a number of characters. Their legs have no or few spines on the underside of the tibial and metatarsal joints of the legs. The last two leg joints have brushes of hairs (scopulae) that extend sideways, particularly on the front legs, giving them a spoon-like (spatulate) appearance. Females have two completely separated spermathecae.
The Euctenizidae are a family of mygalomorph spiders. They are now considered to be more closely related to Idiopidae.
Entychides is a genus of mygalomorph trapdoor spiders in the family Euctenizidae, and was first described by Eugène Simon in 1888. Originally placed with the Ctenizidae, it was moved to the wafer trapdoor spiders in 1985, then to the Euctenizidae in 2012.
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.
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 three species, found in Namibia and South Africa: P. capensis, 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.
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.
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.
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.
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.
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.
Nemesioidina is a clade of avicularioid mygalomorph spiders proposed in 2020, based on a molecular phylogenetic analysis.
