Mygalomorph
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.
Antrodiaetidae
folding-door spiders, folding trapdoor spiders, turret spiders
Antrodiaetidae is a small family of mygalomorph spiders comprising four genera and approximately 37 species. Members are commonly known as folding-door spiders or folding trapdoor spiders due to their distinctive burrow architecture: they construct silk-lined burrows with hinged, collapsible doors that fold or unfold to seal the entrance. The family is primarily distributed in the western and midwestern United States, with two relict species endemic to Japan. Antrodiaetidae are closely related to Atypidae (atypical tarantulas) and share the characteristic low dispersal ability typical of mygalomorph spiders.
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 hageni
Antrodiaetus hageni is a species of folding-door spider in the family Antrodiaetidae, first described by Chamberlin in 1917. It belongs to the infraorder Mygalomorphae, a group of spiders characterized by downward-directed fangs and relatively primitive body plans. The species is known from the United States, though detailed natural history information remains limited in published sources.
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.
Antrodiaetus pugnax
folding-door spider
Antrodiaetus pugnax is a species of folding-door spider in the family Antrodiaetidae. It belongs to the infraorder Mygalomorphae, one of the three main lineages of spiders. The species was originally described as Brachybothrium pugnax by Chamberlin in 1917. Like other members of its genus, it constructs a burrow with a folding door, distinguishing it from trapdoor spiders that use a hinged door.
Antrodiaetus unicolor
folding-door spider, collared spider
Antrodiaetus unicolor is a mygalomorph spider in the family Antrodiaetidae, historically considered a single widespread species but now recognized as a species complex containing multiple cryptic species. These spiders construct silk-lined burrows with folding doors rather than the hinged trapdoors of related families. Research using genomic-scale data has revealed substantial hidden diversity within this morphologically conserved group, particularly in the southern Appalachian Mountains.
Aphonopelma
Aphonopelma is a genus of tarantulas in the family Theraphosidae, comprising the majority of North American tarantula species north of Mexico and many Central American species. The genus includes approximately 54 currently recognized species, though taxonomy remains problematic due to morphological similarity among species. Members are generally large-bodied with leg spans of 6 inches or more, and possess urticating hairs used in defense. The genus exhibits sexual dimorphism, with mature males becoming more active and wander in search of sedentary females.
Aphonopelma catalina
Santa Catalina Mountain Tarantula
Aphonopelma catalina is a tarantula species described in 2016 from the Santa Catalina Mountains of southeastern Arizona. It belongs to a genus of large-bodied, ground-dwelling spiders native to the southwestern United States and Mexico. Like other Aphonopelma species, it exhibits characteristics typical of primitive mygalomorph spiders, including simple genitalia that complicate species identification. The species is endemic to a single mountain range, making it vulnerable to habitat loss.
Aphonopelma chalcodes
Desert Blonde Tarantula, Arizona Blonde Tarantula, Western Desert Tarantula, Mexican Blonde Tarantula
Aphonopelma chalcodes is a large-bodied burrowing tarantula native to the Sonoran and Chihuahuan deserts of the southwestern United States and adjacent Mexico. The species exhibits pronounced sexual dimorphism: females are uniformly tan with a pale, densely hairy carapace that gives the "blonde" common name, while males have black legs, copper-colored cephalothorax, and reddish abdomen. Females are sedentary, occupying deep burrows for their entire lives, whereas mature males abandon their burrows to wander in search of mates during summer monsoon season. The species is notable for its longevity, with females living 24–30 years and males 5–10 years, and for its popularity in the pet trade due to docile temperament and relatively low venom toxicity.
Aphonopelma hentzi
Texas Brown Tarantula, Oklahoma Brown Tarantula, Missouri Tarantula
Aphonopelma hentzi is one of the most common tarantula species in the southern United States, with a broad distribution across the south-central region. Adults typically exceed a four-inch leg span and weigh more than 3 ounces. The body is uniformly dark brown, with coloration becoming more distinct following molting. This species is notable for its male wandering behavior during late summer and fall, when mature males travel substantial distances searching for females. The species serves as host to parasitoid spider wasps, including Pepsis mildei.
Aphonopelma icenoglei
Aphonopelma icenoglei is a species of tarantula in the family Theraphosidae, described in 2016 from California. It is one of 14 new Aphonopelma species identified during a comprehensive taxonomic revision that reduced the previously recognized 55 U.S. species to 29 well-defined species. The species is named in honor of William Icenogle, who contributed specimens and locality data to the study. Like other members of the genus, it is a ground-dwelling burrower native to the southwestern United States.
Aphonopelma iodius
Desert Tarantula, Great Basin Blonde, Fresno County Blonde, Salt Lake City Brown, Northern Blonde
Aphonopelma iodius is a medium-sized tarantula native to the southwestern United States, inhabiting desert regions of California, Nevada, Arizona, and Utah. The species has undergone significant taxonomic revision, with former species A. angusi, A. melanium, A. nevadanum, and A. smithii synonymized under it based on morphological and molecular analyses. Males reach sexual maturity at approximately seven years and emerge from burrows in autumn to seek mates. Females are long-lived, with documented lifespans exceeding thirty years in captivity.
Aphonopelma johnnycashi
Johnny Cash Tarantula
Aphonopelma johnnycashi is a North American tarantula species described in 2016 from specimens collected near Folsom State Prison in California. The species was named in honor of Johnny Cash, the country music singer known as "The Man in Black," referencing both the location and the mature male's solid black coloration. It is one of 14 new species described in a comprehensive taxonomic revision of the genus Aphonopelma, which nearly doubled the number of recognized species in the southwestern United States.
Aphonopelma joshua
Aphonopelma joshua is a species of tarantula in the family Theraphosidae, described by Prentice in 1997. It is native to California, United States. Like other members of the genus Aphonopelma, this species is a large-bodied, ground-dwelling spider that constructs burrows. The genus has undergone significant taxonomic revision, with a 2016 study reducing the number of recognized U.S. species from 55 to 29 based on integrative morphological, molecular, and ecological data.
Aphonopelma madera
Madera Canyon Tarantula
Aphonopelma madera is a species of tarantula in the family Theraphosidae, described in 2016 from specimens collected in the Santa Rita Mountains of southeastern Arizona. The species is named for Madera Canyon, a well-known locality in its range. Like other members of the genus Aphonopelma, it is a large, ground-dwelling spider with urticating defensive hairs. The species is part of a taxonomic revision that split the formerly broadly-defined Aphonopelma chalcodes complex into multiple distinct species based on morphological and molecular data.
Aphonopelma marxi
Grand Canyon Black Tarantula
Aphonopelma marxi is a North American tarantula species in the family Theraphosidae, commonly known as the Grand Canyon Black Tarantula. It is a medium-sized, dark-colored species belonging to the 'Marxi species group' of mainly black, high-elevation tarantulas. The species was first described in 1891 and has undergone taxonomic revision, with two former species (A. behlei and A. vogelae) now recognized as synonyms. It is widely distributed but difficult to observe due to its fossorial habits.
Aphonopelma paloma
Paloma dwarf, Paloma Dwarf Tarantula
Aphonopelma paloma, commonly known as the Paloma dwarf, is the smallest known species of tarantula, with a leg span of approximately 5 cm. This diminutive theraphosid is native to southern Arizona and is notable for its extremely small burrow entrances, measuring only 5–10 mm in width. The species was described by Prentice in 1993 and is considered difficult to detect in the field due to its small size and cryptic habits.
Aphonopelma steindachneri
Steindachner's Ebony Tarantula
Aphonopelma steindachneri, commonly known as Steindachner's Ebony Tarantula, is a New World terrestrial tarantula native to arid regions of California and Baja California, Mexico. The species reaches 12–13 cm in diagonal leg span and exhibits dark velvet black to deep brown coloration. It constructs and occupies burrows in open ground, emerging primarily at night to forage. Males become most visible during summer and fall breeding seasons when they leave burrows to search for mates. The species faces predation from spider wasps, centipedes, scorpions, and solifugids.
Apomastus
Apomastus is a genus of mygalomorph spiders in the family Euctenizidae, endemic to southern California and described in 2002. The genus contains only two species, A. kristenae and A. schlingeri, both restricted to the Los Angeles Basin and surrounding hills. Females of both species are morphologically indistinguishable, requiring molecular or male morphological analysis for identification. The genus occupies habitat highly vulnerable to urban development.
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.
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 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.
Atypoides riversi
California Turret Spider, turret spider
Atypoides riversi, commonly known as the California turret spider, is a medium-sized mygalomorph spider endemic to northern and central California. It constructs distinctive burrows topped with a turret-like structure made of soil, vegetation, and silk. Females are larger than males, with body lengths ranging from 13 to 18 millimeters. Research indicates this species represents a species complex, with multiple genetically distinct populations separated by geographic barriers.
Atypus
Purse-web Spider, Purseweb Spider
Atypus is a genus of mygalomorph spiders commonly known as purse-web spiders, first described by Latreille in 1804. These spiders construct distinctive silk tubes (purse-webs) that extend from underground burrows vertically along tree bases, fences, or other surfaces. The genus occurs across Eurasia and northern Africa, with 38 described species as of 2025. Atypus species are perennial, with females living 8–10 years, and conduct nearly all life activities—including predation, mating, and egg-laying—within their sealed webs. One Asian species, A. karschi, has been introduced and established in southeastern Pennsylvania, USA.
Atypus karschi
Karsch's Purseweb Spider
Atypus karschi is a mygalomorph spider native to East Asia (Korea, China, Taiwan, Japan) that has been introduced and established in southeastern Pennsylvania, USA. It constructs distinctive camouflaged tubular purse-webs attached to trees, shrubs, or walls, with a portion buried underground. The species was previously misidentified in North America as A. snetsingeri, but genetic analysis confirmed conspecificity with Asian populations. It is the first documented case of an introduced purse-web spider.
Bothriocyrtum
California trap-door spiders
Bothriocyrtum is a genus of mygalomorph spiders in the family Halonoproctidae, established by Eugène Simon in 1891. The genus comprises three recognized species native to North America and Taiwan. These spiders are commonly known as trap-door spiders, constructing burrows with hinged silk-lidded doors. The genus was separated from Cyrtocarenum based on distinct morphological features including eye arrangement and width of separation between certain structures.
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.
Calisoga
Calisoga is a genus of mygalomorph spiders in the family Nemesiidae, first described by Ralph Vary Chamberlin in 1937. The genus comprises five species, all endemic to the United States. Calisoga spiders are notable for their distribution pattern around the Central Valley of California, which has made them a significant study system for understanding ring speciation dynamics in mygalomorph spiders. Genetic studies indicate this is a lineage-rich complex with complex evolutionary history.
Calisoga longitarsis
False Tarantula
Calisoga longitarsis is a mygalomorph spider in the family Nemesiidae, commonly known as the False Tarantula. It is one of several species in the genus Calisoga distributed around the Central Valley of California. The species has been studied as part of research on ring speciation dynamics in California mygalomorph spiders. It is frequently observed and photographed, with over 2,300 records on iNaturalist.
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.
Euagridae
Spiny Curtain-web Spiders
Euagridae is a family of mygalomorph spiders commonly known as Spiny Curtain-web Spiders. The group was established as a tribe by Robert Raven in 1979, elevated to subfamily rank in 1985, and recognized as a full family by Opatova et al. in 2020 based on molecular phylogenetic analyses. As of 2025, the family comprises fourteen genera. Members are distinguished by their spiny morphology and curtain-web construction behavior.
Euagrus chisoseus
Spiny Curtain Web Spider
Euagrus chisoseus is a mygalomorph spider in the family Euagridae, described by Gertsch in 1939. It is commonly known as the Spiny Curtain Web Spider. The species occurs in the southwestern United States and Mexico. As a member of the Euagridae, it constructs sheet-like or curtain webs rather than the vertical orb webs of many other spider groups.
Euctenizidae
Wafer-lid Trapdoor Spiders
Euctenizidae is a family of mygalomorph spiders elevated from subfamily status in 2012. The family contains approximately 79 described species across eight genera, including Aptostichus, Myrmekiaphila, and Promyrmekiaphila. Members are characterized by their fossorial lifestyle and construction of silk-lined burrows with distinctive trapdoors. The family is now considered more closely related to Idiopidae than to other trapdoor spider families.
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.
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.
Hexurella
dwarf funnel web spiders
Hexurella is a genus of dwarf funnel web spiders (Mygalomorphae, Hexurellidae) comprising some of the smallest mygalomorph spiders in the world. Adults measure 2.5–5 mm in body size. The genus represents a phylogenetically ancient, relictual lineage that diverged from other atypoids approximately 300 million years ago. As of 2026, the genus contains eight species, with four described in a 2023 taxonomic revision. Several species have highly restricted geographic ranges and may warrant conservation attention.
Hexurella apachea
Hexurella apachea is a species of mygalomorph spider in the family Hexurellidae, described by Gertsch and Platnick in 1979. It is native to the United States, specifically occurring in the southwestern borderlands region. As a dwarf funnel web spider, it belongs to a lineage of small-bodied mygalomorphs with distinctive burrowing habits.
Hexurella rupicola
Hexurella rupicola is a dwarf funnel web spider species described by Gertsch and Platnick in 1979. It belongs to the family Hexurellidae, a small group of mygalomorph spiders. The species is native to the United States, with records from the US-Mexico borderlands region. It is one of several species within the genus Hexurella that have been subject to recent taxonomic revision using molecular phylogenetic methods.
Hexurellidae
Micro Dwarf Tarantulas
Hexurellidae is a monogeneric family of mygalomorph spiders containing only the genus Hexurella, established in 2019 based on phylogenomic evidence showing it as sister to all remaining atypoids. This relictual lineage diverged from other atypoids approximately 300 million years ago. Members are among the smallest mygalomorph spiders worldwide (2.5–5 mm as adults), with seven recognized species distributed in the US-Mexico borderlands. The family exhibits strict microhabitat preferences and micro-endemism, making it significant for sky island biogeography research.
Megahexura fulva
Tawny Dwarf Tarantula
Megahexura fulva is a small mygalomorph spider native to the western United States. It constructs an exposed sheet web with a funnel-shaped retreat in holes and crevices along ravine banks. The species is the sole member of the genus Megahexura, which was formerly placed in Mecicobothriidae but is now recognized in its own family, Megahexuridae. These spiders are among the smallest mygalomorphs, with body lengths typically under 10 mm.