The Mygalomorphae, or mygalomorphs, are an infraorder of spiders, and comprise one of three major groups of living spiders with over 3,000 species, found on all continents except Antarctica. Many members are known as trapdoor spiders due to their creation of 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.
Atracidae is a family of mygalomorph spiders, commonly known as Australian funnel-web spiders or atracids. It has been included as a subfamily of the Hexathelidae, but is now recognised as a separate family. All members of the family are native to Australia. Atracidae consists of three genera: Atrax, Hadronyche, and Illawarra, comprising 35 species. Some members of the family produce venom that is dangerous to humans, and bites by spiders of six of the species have caused severe injuries to victims. The bites of the Sydney funnel-web spider and northern tree-dwelling funnel-web spider are potentially deadly, but no fatalities have occurred since the introduction of modern first-aid techniques and antivenom.
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.
Hexathelidae is a family of mygalomorph spiders. It is one of a number of families and genera of spiders known as tunnelweb or funnel-web spiders. In 2018, the family was substantially reduced in size by genera being moved to three separate families: Atracidae, Macrothelidae and Porrhothelidae.
Cybaeidae is a family of spiders first described by Nathan Banks in 1892. The diving bell spider or water spider Argyroneta aquatica was previously included in this family, but is now in the family Dictynidae.
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 more than 48,500 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.
Austrochilidae is a small spider family with nine species in two genera. Austrochilus and Thaida are endemic to the Andean forest of central and southern Chile and adjacent Argentina.
The Eresoidea or eresoids are a group of araneomorph spiders that have been treated as a superfamily. As usually circumscribed, the group contains three families: Eresidae, Hersiliidae and Oecobiidae. Studies and reviews based on morphology suggested the monophyly of the group; more recent gene-based studies have found the Eresidae and Oecobiidae to fall into different clades, placing doubt on the acceptability of the taxon. Some researchers have grouped Hersiliidae and Oecobiidae into the separate superfamily Oecobioidea, a conclusion supported in a 2017 study, which does not support Eresoidea.
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.
Atypoides is a genus of North American folding trapdoor spiders. It was first described by Octavius Pickard-Cambridge in 1883, and it has only been found in United States. It was synonymized with the genus Antrodiaetus in 2007, but was restored to its former independent status in 2019. As of November 2021, it contains only three species: A. gertschi, A. hadros, and A. riversi.
The Euctenizidae are a family of mygalomorph spiders. They are now considered to be more closely related to Idiopidae.
Orbiculariae is a potential clade of araneomorph spiders, uniting two groups that make orb webs. Phylogenetic analyses based on morphological characters have generally recovered this clade; analyses based on DNA have regularly concluded that the group is not monophyletic. The issue relates to the origin of orb webs: whether they evolved early in the evolutionary history of entelegyne spiders, with many groups subsequently losing the ability to make orb webs, or whether they evolved later, with fewer groups having lost this ability. As of September 2018, the weight of the evidence strongly favours the non-monophyly of "Orbiculariae" and hence the early evolution of orb webs, followed by multiple changes and losses.
Hexura is a genus of American folding trapdoor spiders that was first described by Eugène Louis Simon in 1884. As of September 2019 it contains two species, found in the United States: H. picea and H. rothi. Originally placed with Mecicobothriidae, it was moved to Antrodiaetidae in 2019.
Synspermiata is a clade of araneomorph spiders, comprising most of the former "haplogynes". They are united by having simpler genitalia than other araneomorph spiders, lacking a cribellum, and sharing an evolutionary history of synspermia – a particular way in which spermatozoa are grouped together when transferred to the female.
Toxopidae is a small family of araneomorph spiders, first described in 1940. For many years it was sunk into Desidae as a subfamily, although doubts were expressed as to whether this was correct. A large-scale molecular phylogenetic study in 2016 led to the family being revived.
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.
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.
