The Mesothelae are a suborder of spiders that includes a single extant family, Liphistiidae, and a number of extinct families. This suborder is thought to form the sister group to all other living spiders, and to retain ancestral characters, such as a segmented abdomen with spinnerets in the middle and two pairs of book lungs. Members of Liphistiidae are medium to large spiders with eight eyes grouped on a tubercle. They are found only in China, Japan, and southeast Asia. The oldest known Mesothelae spiders are known from the Carboniferous, over 300 million years ago.
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.
The family Cyrtaucheniidae, known as wafer-lid trapdoor spiders, are a widespread family of Mygalomorphae spiders.
Idiopidae, also known as armored trapdoor spiders, is a family of mygalomorph spiders first described by Eugène Simon in 1889. They have a large body similar to tarantulas.
Microstigmatidae is a small family of spiders with about 25 described species in eight genera. They are small ground-dwelling and free-living spiders that make little use of silk.
Barychelidae, also known as brushed trapdoor spiders, is a spider family with about 300 species in 42 genera.
Idiosoma is a genus of Australian armoured trapdoor spiders that was first described by Anton Ausserer in 1871. Originally placed with the Ctenizidae, it was moved to the armoured trapdoor spiders in 1985. The name is derived from the Greek ἴδιος, meaning "individual, unique", and σῶμα, meaning "body", referring to the distinctive structure of the abdomen.
Atypus, also called purseweb spiders, is a genus of atypical tarantulas first described by Pierre André Latreille in 1804. It occurs in Eurasia, with one species reaching into North Africa, and one species in the USA. Only three of the described species occur in Europe: A. piceus, A. affinis, and A. muralis.
Macrothele is a genus of mygalomorph spiders in the family Macrothelidae, and was first described by A. Ausserer in 1871. Most species occur in Asia, from India to Japan, and Java, with five found in Africa, and two in Europe. The name is derived from Ancient Greek μακρός ("makro-"), meaning "big", and θηλή ("thele"), referring to the spinnerets.
Liphistius is a genus of basal trapdoor spiders in the family Liphistiidae. They are found in Japan, China, and Southeast Asia.
Myrmekiaphila is a genus of North American mygalomorph trapdoor spiders in the family Euctenizidae, and was first described by G. F. Atkinson in 1886. All described species are endemic to the southeastern United States.
Latouchia is a genus of Asian mygalomorph spiders in the family Halonoproctidae, first described by Reginald Innes Pocock in 1901. Originally placed with the Ctenizidae, it was moved to the Halonoproctidae in 2018.
Conothele is a genus of mygalomorph spiders in the family Halonoproctidae, first described by Tamerlan Thorell in 1878. Originally placed with the Ctenizidae, it was moved to the Halonoproctidae in 2018.
Qiongthela is a genus of spiders in the family Liphistiidae. As of 2021, it contains 14 species.
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.
Cyclocosmia ricketti, commonly known as the Chinese hourglass spider, is a species of trapdoor spider of the genus Cyclocosmia, which refers specifically to mygalomorphus animals. Cyclocosmia ricketti is native to China and it was first described in 1901 by Mary Agard Pocock. They are characterized by their truncated abdomen and the rigid disk at the bottom with a pattern.
