Trapdoor-spider
Guides
Aliatypus
Aliatypus is a genus of North American folding trapdoor spiders in the family Antrodiaetidae. First described by C.P. Smith in 1908, these spiders are most closely related to Antrodiaetus, though they have convergently evolved trapdoor-building behavior similar to Ctenizidae. They are notable for building wafer-like trapdoor burrows in hot, dry habitats where their collar-door relatives cannot survive. The genus contains fourteen species as of 2026, with distributions concentrated in the western United States, particularly California. Their sedentary lifestyle and limited dispersal make them valuable subjects for biogeographic studies.
Aliatypus californicus
California folding-door spider, California folding trapdoor spider
Aliatypus californicus is a species of folding-door spider in the family Antrodiaetidae. It is found in the United States, specifically in California. The species constructs burrows with a hinged, folding trapdoor made of silk and soil debris. It is one of several species in the genus Aliatypus studied for its burrow architecture and mygalomorph spider systematics.
Aliatypus gulosus
Aliatypus gulosus is a species of folding trapdoor spider in the family Antrodiaetidae. It was described by arachnologist Frederick A. Coyle in 1975. Like other members of its genus, it constructs burrows with hinged, camouflaged trapdoors to capture prey. The species is part of a group studied by the Jason Bond laboratory at UC Davis for its systematics and natural history.
Antrodiaetus
folding trapdoor spiders, turret spiders
Antrodiaetus is a genus of mygalomorph spiders in the family Antrodiaetidae, first described by Anton Ausserer in 1871. The genus includes species found in the United States and Japan, with the name derived from Greek roots meaning 'cave-dwelling.' These spiders are commonly known as folding trapdoor spiders or turret spiders due to their distinctive burrow architecture. Research on Antrodiaetus has been significant in arachnological studies of species delimitation, particularly using molecular approaches to reveal cryptic diversity in morphologically similar populations.
Antrodiaetus montanus
Mountain Folding-Door Spider
Antrodiaetus montanus is a mygalomorph spider in the family Antrodiaetidae, commonly known as folding-door spiders. The species constructs silk-lined burrows with hinged, trapdoor-like closures made of silk and soil. It is native to mountainous regions of the western United States. Like other antrodiaetids, it exhibits fossorial behavior and is rarely observed above ground except during dispersal events.
Antrodiaetus pacificus
Pacific Foldingdoor Spider
Antrodiaetus pacificus is a mygalomorph spider native to the Pacific Northwest of North America, ranging from San Francisco Bay to Alaska. It is the northernmost mygalomorph spider on the continent. The species was first described by Eugène Louis Simon in 1884 under the name Brachybothrium pacificum. It constructs burrows in soft substrates and exhibits year-round activity with peak mating season between early June and late November.
Apomastus kristenae
Apomastus kristenae is a wafer-lid trapdoor spider described by Bond in 2004. It is one of two recognized species in the genus Apomastus, both endemic to restricted regions of southern California. Females are morphologically indistinguishable from the congeneric A. schlingeri, requiring molecular or geographic data for identification. The species occupies a habitat under severe pressure from urban development.
Apomastus schlingeri
Apomastus schlingeri is a venomous trapdoor spider species described by Bond & Opell in 2002. It was originally misidentified as Aptostichus schlingeri before taxonomic revision placed it in the genus Apomastus. The species is known for producing a complex of neurotoxic peptides called aptotoxins, which function as voltage-gated sodium channel blockers. It is one of only two known species in the genus Apomastus, both restricted to the United States.
Aptostichus
Aptostichus is a genus of mygalomorph trapdoor spiders in the family Euctenizidae, described by Eugène Simon in 1891. The genus contains 41 described species distributed primarily in southern California, with some species extending into northern California, Mexico, and the Channel Islands. These spiders are notable for constructing silk-lined burrows with thin wafer-like trapdoors, though unlike some related genera, they do not seal side chambers with additional trapdoors. Several species have been named after prominent figures, reflecting both scientific interest and public engagement in arachnology.
Aptostichus atomarius
San Bernardino hills trapdoor spider
Aptostichus atomarius, the San Bernardino hills trapdoor spider, is a wafer-lid trapdoor spider in the family Euctenizidae. First described by Eugène Simon in 1891, this species is native to the United States. Like other members of its genus, it constructs silk-lined burrows with wafer-like trapdoor lids. The species is part of a diverse genus of trapdoor spiders found primarily in California and surrounding regions.
Aptostichus chemehuevi
Chemehuevi Desert Trapdoor Spider
Aptostichus chemehuevi is a species of trapdoor spider in the family Euctenizidae, described by arachnologist Jason Bond in 2012. It belongs to a genus of mygalomorph spiders known for constructing silk-lined burrows with hinged trapdoor lids. The species epithet references the Chemehuevi people, a Native American group whose traditional territory includes parts of the southwestern United States where this spider occurs. Like other Aptostichus species, it is a fossorial predator with limited dispersal capability.
Aptostichus miwok
Miwok Trapdoor Spider
Aptostichus miwok is a trapdoor spider species in the family Euctenizidae, described by arachnologist Jason Bond in 2008. The species name honors the Coast Miwok people, Indigenous inhabitants of coastal California from the Golden Gate northward. Like other Aptostichus species, it constructs silk-lined burrows with wafer-like trapdoor lids. The species belongs to a genus that has received notable attention for species named after celebrities and public figures.
Aptostichus sarlacc
Sarlacc Trapdoor Spider
Aptostichus sarlacc is a trapdoor spider species described by Jason Bond in 2012 from the Mojave Desert. The species epithet references the Sarlacc creature from George Lucas' Star Wars, a fictional desert-dwelling organism. It belongs to a genus of trapdoor spiders known for constructing silk-lined burrows with camouflaged trapdoor lids made of soil, vegetation, and silk. The species was among 33 new Aptostichus species described from the American Southwest in a major taxonomic revision.
Aptostichus simus
Southern Coastal Dune Trapdoor Spider
Aptostichus simus is a medium-sized mygalomorph trapdoor spider endemic to coastal sand dune habitats of California and Baja California, Mexico. This fossorial species constructs deep, silk-lined burrows with camouflaged trapdoor lids made of sand and silk, typically situated at the base of native dune vegetation. Recent integrative taxonomic research using genomic data has revealed significant cryptic diversity within this species complex, including the description of a new cryptic species, A. ramirezae, from Moss Landing State Beach. The species exhibits deep genetic divergence dating to 2-3 million years ago despite morphological homogeneity, with populations showing extreme habitat specificity that makes them vulnerable to coastal habitat degradation.
Bothriocyrtum californicum
California trapdoor spider, California cork-lid trapdoor spider
Bothriocyrtum californicum is a cork-lid trapdoor spider endemic to arid regions of the southwestern United States and northwestern Mexico. This mygalomorph spider constructs burrows with a hinged, cork-like door made of soil and silk, which it uses to ambush passing prey. Males are smaller than females, a reversal of typical sexual dimorphism in spiders. The species is notable as the first representative of its genus and family to have its mitochondrial genome sequenced.
Cyclocosmia
cork-lid trapdoor spider, Oreo spider (misnomer)
Cyclocosmia is a genus of mygalomorph trapdoor spiders in the family Halonoproctidae, comprising thirteen species distributed across North America (USA, Mexico) and Southeast Asia (China, Thailand, Vietnam, Laos). These spiders are distinguished by their unique abdominal morphology: an abruptly truncated, hardened posterior disc strengthened by ribs and grooves, used to seal burrow entrances when threatened. The genus was first described by Anton Ausserer in 1871 and serves as the type genus for Halonoproctidae. Species are long-lived, slow-maturing, and have demanding habitat requirements that make them rare in collections despite local abundance.
Cyclocosmia torreya
Torreya Trapdoor Spider
Cyclocosmia torreya is a cork-lid trapdoor spider endemic to the Apalachicola River region of Florida. The species constructs burrows sealed with a hardened, disk-like abdominal shield that serves as a defensive plug against predators. It belongs to a genus characterized by this unique abdominal truncation, which has evolved independently as an anti-predator adaptation. The species is rare and poorly known, with only a handful of documented observations.
Cyclocosmia truncata
Ravine Trapdoor Spider
Cyclocosmia truncata is a cork-lid trapdoor spider native to the United States. It constructs burrows in soil and employs a distinctive defensive behavior called phragmosis, using its rigid, disc-shaped abdomen to plug the burrow entrance when threatened. The species belongs to the mygalomorph spider group, which includes tarantulas and other trapdoor spiders. It is not considered dangerous to humans despite possessing venom typical of spiders.
Entychides
Entychides is a genus of mygalomorph trapdoor spiders in the family Euctenizidae, first described by Eugène Simon in 1888. The genus has undergone several family reassignments, originally placed in Ctenizidae, then moved to wafer trapdoor spiders (Cyrtaucheniidae) in 1985, and finally to Euctenizidae in 2012. It contains four recognized species distributed across Mexico, the southwestern United States, and the Lesser Antilles.
Eucteniza relata
Southwestern Trapdoor Spider
Eucteniza relata, commonly known as the southwestern trapdoor spider, is a species of wafer-lid trapdoor spider in the family Euctenizidae. It is found in the United States and Mexico. The species belongs to a family of mygalomorph spiders known for constructing burrows with trap doors made of soil, vegetation, and silk.
Halonoproctidae
Saddle-legged Trapdoor Spiders
Halonoproctidae is a family of mygalomorph spiders elevated from subfamily status in 2018 based on molecular phylogenetic studies that demonstrated Ctenizidae was paraphyletic. The family includes six genera and approximately 145 species of trapdoor spiders distributed across North and Central America, the Caribbean, southern Europe, North Africa, Asia, and Australasia. These spiders construct silk-lined burrows with trapdoors and are characterized by medium to large body size, somber coloration, and distinctive morphological features including sigillae on the sternum and modified spines on the legs.
Hebestatis theveneti
Thevenet's Trapdoor Spider
Hebestatis theveneti is a species of cork-lid trapdoor spider in the family Halonoproctidae. It is native to the United States and constructs burrows sealed with camouflaged, hinged trapdoors. The species is one of several trapdoor spiders maintained in research collections for study of arachnid behavior and systematics.
Hexura
Hexura is a genus of American folding trapdoor spiders first described by Eugène Louis Simon in 1884. The genus contains two species: H. picea and H. rothi, both found in the United States. These spiders construct burrows with hinged, folding trapdoors. The genus has undergone taxonomic revision, with placement in Antrodiaetidae confirmed by 2019.
Myrmekiaphila
Ant-loving trapdoor spiders
Myrmekiaphila is a genus of mygalomorph trapdoor spiders in the family Euctenizidae, endemic to the southeastern United States. The genus was first described by G.F. Atkinson in 1886 and has undergone several taxonomic revisions, most recently placed in Euctenizidae in 2012. These spiders construct subterranean silk-lined burrows with silken-soil trap doors, and some species uniquely build side chambers closed by secondary trap doors. The genus name derives from Greek roots meaning 'ant-loving,' referencing their frequent association with ant nests.
Myrmekiaphila comstocki
Comstock's Wafer Trapdoor Spider
Myrmekiaphila comstocki is a trapdoor spider in the family Euctenizidae, commonly known as the wafer-lid trapdoor spiders. It belongs to the infraorder Mygalomorphae, a group of ancient spiders that includes tarantulas and funnel-web spiders. The species constructs silk-lined burrows with hinged, wafer-like trapdoors. Its distribution spans the United States and Mexico.
Neoapachella rothi
Neoapachella rothi is a mygalomorph trapdoor spider and the sole species in its genus. It was described in 2002 and is endemic to the southwestern United States. The species name honors arachnologist Vincent D. Roth, while the genus name references the Apache peoples. Adults reach approximately 20.7 mm in body length.
Promyrmekiaphila
Promyrmekiaphila is a genus of mygalomorph trapdoor spiders endemic to California. First described by Schenkel in 1950, the genus currently contains three species: P. clathrata, P. winnemem, and P. korematsui. These spiders construct silk-lined burrows with wafer-like trapdoor lids and exhibit strong geographic population structuring with deep genetic divergence, particularly within P. clathrata. The genus is notable for morphological conservation despite considerable genetic differentiation, representing a cryptic species complex.
Promyrmekiaphila clathrata
wafer-lid trapdoor spider
Promyrmekiaphila clathrata is a species of wafer-lid trapdoor spider in the family Euctenizidae, endemic to California. It constructs silk-lined burrows up to 30 cm deep in soil, covered with a wafer-like trapdoor made of silk and soil. The species exhibits deep genetic population structure across its range but is not divided into multiple species. It is one of three described species in the genus Promyrmekiaphila.