Cave-dwelling
Guides
Aglossa pinguinalis
Large Tabby, Grease Moth
Aglossa pinguinalis is a pyralid moth commonly known as the large tabby or grease moth. The species exhibits a rare feeding strategy among Lepidoptera: coprophagy, with larvae consuming animal feces. Larval development spans approximately two years, and the species shows strong habitat affinity for caves and sheltered environments. It is native to the Palearctic region but has been introduced to North America and New Zealand.
Amblypygi
whip spiders, tailless whip scorpions, amblypygids
Amblypygi is an ancient order of arachnids comprising approximately 280 species across five families. These nocturnal predators are characterized by extremely elongated first pair of legs modified as sensory "whips" and raptorial pedipalps for capturing prey. They lack venom glands, silk production, and the tail-like flagellum present in their relatives the whip scorpions (Uropygi). Several species exhibit unusual social behaviors including maternal care and kin recognition.
Anapistula
Anapistula is a genus of minute araneomorph spiders in the family Symphytognathidae, established by Gertsch in 1941. The genus comprises 28 described species distributed across tropical and subtropical regions of Asia, South America, and Europe. Members exhibit diverse habitat preferences: approximately 18 species occur in leaf litter, soil, and mosses, while seven are obligate cave-dwellers (troglobites) and one inhabits cave entrances. The genus includes some of the smallest spiders known, with A. ataecina from Portugal representing both the first European record of the family and one of the smallest described spider species.
Androniscus
Androniscus is a genus of small woodlice in the family Trichoniscidae, established by Verhoeff in 1908. The genus includes the well-known species Androniscus dentiger, commonly called the rosy or pink woodlouse. Members of this genus are characterized by their small size, distinctive coloration, and association with calcareous environments. Some populations show cave-adapted ecology, particularly in the southern part of their range.
Anthroleucosomatidae
Anthroleucosomatidae is a family of small to medium-sized millipedes in the order Chordeumatida, with approximately 19 genera and at least 40 described species. The family exhibits a core distribution centered on the Balkans and Caucasus region, extending eastward to Iran and central Siberia, with one highly disjunct North American species in Washington State. Many species are troglobionts (obligate cave-dwellers), including the world's deepest-occurring millipede, Heterocaucaseuma deprofundum, found below 2,000 meters in Krubera-Voronja Cave. The family shows exceptional diversity in the Caucasus, where 15 new genera and 36 new species were described in a single monograph.
Archoleptoneta
Archoleptoneta is a genus of small spiders in the family Archoleptonetidae, containing only two known species restricted to the United States. The genus was established by Gertsch in 1974 and is characterized by reduced eyes and troglobitic adaptations. These spiders are among the least studied North American arachnids, with very few observations recorded.
Arrhopalites
springtails
Arrhopalites is a genus of globular springtails (Collembola: Symphypleona) in the family Arrhopalitidae. The genus comprises approximately 40 valid species, with roughly half considered troglobionts—obligate cave-dwelling organisms. Species occur across diverse habitats including cave systems, forest leaf litter, and soil environments, with distribution spanning the Neotropical Region, Asia, Europe, and other regions. The genus is taxonomically significant for phylogenetic studies of Symphypleona, though many aspects of its biology remain understudied.
Arrhopalitidae
Arrhopalitidae is a family of springtails (Collembola) in the order Symphypleona, superfamily Katiannoidea. The family includes three genera: Arrhopalites, Pygmarrhopalites, and Troglopalites. Many species are obligate cave-dwellers (troglobionts) exhibiting pronounced troglomorphy, including reduced pigmentation, elongated appendages, and modified sensory structures. The family has a sister-group relationship with Katiannidae.
Artema
Giant Cellar Spiders
Artema is a genus of cellar spiders (family Pholcidae) first described by Charles Athanase Walckenaer in 1837. The genus includes some of the largest pholcid spiders and is primarily distributed from West Africa through Central Asia to Pakistan. One species, A. atlanta, has been introduced worldwide. The genus comprises twelve recognized species as of October 2025.
Bembidiini
Bembidiini is a large tribe of ground beetles (Carabidae) comprising over 120 genera and approximately 3,100 described species. Members are predominantly small to minute beetles, often found in riparian, intertidal, subterranean, and arboreal habitats. The tribe includes notable subtribes such as Xystosomina (arboreal tropical beetles) and Anillina (small litter-dwelling forms), as well as the subtribe Lovriciina containing highly specialized cave-dwelling species. Many species exhibit narrow habitat specificity, including intertidal gravel beaches and tropical forest canopy systems.
Blaniulidae
Thin Snake Millipedes
Blaniulidae is a family of julid millipedes characterized by extremely elongated, slender bodies with length-to-width ratios reaching 30:1. Members possess distinctive ozadenes (odiferous defensive glands) visible as spots on each segment, and may have eyes present or absent depending on species. The family exhibits diverse habitat preferences including leaf litter, soil, caves, and synanthropic environments. Several genera contain troglobitic species restricted to subterranean habitats, while others are widespread across Europe and have been introduced to other continents.
Blattellinae
wood cockroaches
Blattellinae is a subfamily of Ectobiidae containing approximately 70 genera. It includes the globally distributed German cockroach (Blattella germanica), a major household pest, as well as several endangered species such as those in Hololeptoblatta and Miriamrothschildia. The subfamily exhibits diverse ecological adaptations, with members occupying habitats ranging from wetlands and grasslands to caves and human dwellings.
Brachyceridae
Brachyceridae is a family of weevils (Coleoptera: Curculionoidea) containing at least 150 genera. The family has been treated historically as a subfamily of Curculionidae, but is now recognized as distinct. Some constituent genera, such as Absoloniella, contain blind, wingless species restricted to Mediterranean regions. The family belongs to the superfamily Curculionoidea, placing it among the true weevils.
Calicina mariposa
Calicina mariposa is a species of armoured harvestman in the family Phalangodidae. It was originally described as Sitalcina mariposa by Briggs in 1968 before being transferred to the genus Calicina. The species is known from North America. Very little published information exists regarding its biology or ecology.
Callipodida
Crested Millipedes
Callipodida is an order of millipedes comprising approximately 130 species across three extant suborders and seven families. Members are characterized by elongated bodies with 40–60 segments, reaching up to 100 mm in length, and often display distinctive dorsal crests or ridges. The order exhibits a disjunct distribution across the Northern Hemisphere, with populations in North America, Europe, western Asia, southern China, and Southeast Asia. Sexual maturity is achieved through teloanamorphosis, with males possessing a single pair of gonopods derived from the seventh leg pair.
Calymmaria emertoni
Calymmaria emertoni is a small true spider in the family Cybaeidae (formerly Hahniidae). It is one of approximately 31 Calymmaria species found north of Mexico, with most species restricted to the Pacific coast region. This species is notable for its distinctive basket-shaped web and nocturnal habits.
Camillidae
Camillidae is a small family of minute flies (2–3.5 mm) within the superfamily Ephydroidea. The family contains five genera, four extant and one fossil. Adults are slender, lustrous black flies with hyaline wings and distinctive bristle patterns on the head and thorax. Larval biology is poorly known, though they have been reared from bat guano and rock hyrax dung, suggesting a role in decomposing organic matter in sheltered environments.
Catops
Catops is a genus of small carrion beetles in the family Leiodidae, subfamily Cholevinae, established by Paykull in 1798. The genus comprises approximately 16 described species distributed across the Holarctic region. Several species are associated with cave habitats, including the Iranian endemic Catops farsicus.
Catoptrichus
Catoptrichus is a genus of small carrion beetles in the family Leiodidae, subfamily Cholevinae. Members of this genus are eyeless, subterranean-adapted beetles associated with cave and soil habitats. The genus was established by Andrew Murray in 1856 and is placed in the subtribe Catopina.
Causeyella
Causeyella is a genus of troglobitic (cave-dwelling) millipedes in the family Trichopetalidae, order Chordeumatida. The genus was established by Shear in 2003 and comprises three species: C. causeyae, C. dendropus, and C. youngsteadtorum. These millipedes are restricted to cave habitats in the southern Ozarks region of the United States.
Centromerus
dwarf spiders
Centromerus is a genus of dwarf spiders in the family Linyphiidae, containing approximately 88 species and two subspecies. The genus has a broad distribution spanning the Holarctic region, with species recorded across Europe, North America, Asia, and North Africa. Many species exhibit restricted geographic ranges, while a few such as C. sylvaticus have exceptionally wide distributions. The genus was established by Dahl in 1886.
Ceratolasmatidae
Ceratolasmatidae is a family of harvestmen (Opiliones) comprising eleven described species across four genera. The family's monophyly is questionable, with three potentially distinct lineages showing affinities to different harvestman families: Ceratolasma and Acuclavella related to Ischyropsalididae, Hesperonemastoma related to Sabaconidae, and Crosbycus possibly warranting separate family status. Body sizes range from less than 1 mm to 6 mm depending on genus.
Ceuthophilinae
cave crickets, camel crickets, spider crickets
Ceuthophilinae is a subfamily of Rhaphidophoridae comprising North American cave crickets. Members exhibit morphological adaptations to subterranean life including reduced eyes and depigmentation. They serve as hosts for parasitic larval mites in the group Parasitengona. The subfamily includes genera such as Ceuthophilus and Hadenoecus.
Ceuthophilus chiricahuae
Chiricahua cave cricket
Ceuthophilus chiricahuae is a species of camel cricket (family Rhaphidophoridae) endemic to North America. The species was described by Hubbell in 1936 and is named for the Chiricahua Mountains region. Like other members of the genus Ceuthophilus, it is wingless and adapted to cool, dark, moist habitats. Very few observations of this species have been recorded, with only six documented occurrences in biodiversity databases.
Ceuthophilus guttulosus guttulosus
camel cricket, cave cricket
Ceuthophilus guttulosus guttulosus is a subspecies of camel cricket in the family Rhaphidophoridae. Like other members of the genus Ceuthophilus, it is wingless and possesses exceptionally long antennae adapted for navigation in dark environments. The species exhibits the characteristic hump-backed appearance that gives camel crickets their common name. This subspecies has been recorded from several eastern and midwestern U.S. states.
Ceuthophilus guttulosus nigricans
Ceuthophilus guttulosus nigricans is a subspecies of camel cricket in the family Rhaphidophoridae. Like other members of the genus Ceuthophilus, it is wingless, nocturnal, and adapted to dark, humid environments. The subspecies designation indicates darker coloration compared to the nominate form. It has been recorded in the eastern United States from Indiana to North Carolina.
Ceuthophilus stygius
Kentucky cave cricket, cave camel cricket, Stygian Cave Cricket
Ceuthophilus stygius is a camel cricket in the family Rhaphidophoridae, commonly known as the Kentucky cave cricket or Stygian Cave Cricket. It is native to North America, with records from the southeastern United States and Indiana. As a member of the genus Ceuthophilus, it shares traits with other cave crickets including elongated antennae, powerful jumping legs, and adaptation to dark, damp environments. The species has been studied for its metabolic and water economy physiology in relation to body size and temperature.
Chilopoda
Centipedes
Chilopoda is a class of venomous, predatory arthropods comprising the centipedes. These elongated metameric animals possess one pair of legs per body segment, with leg counts ranging from 30 to 354 depending on species. Centipedes are distinguished from millipedes (class Diplopoda) by their single pair of legs per segment, flattened body profile, and venomous forcipules derived from modified first leg pairs. The class contains four extant orders: Scutigeromorpha (house centipedes), Lithobiomorpha (stone centipedes), Geophilomorpha (soil centipedes), and Scolopendromorpha (giant centipedes). All are obligate carnivores with predatory lifestyles.
Chionea obtusa
Chionea obtusa is a wingless crane fly in the family Limoniidae, one of sixteen North American species in the genus Chionea commonly known as "snow flies." Described by George Byers in 1983, this species inhabits the Nearctic region of western North America. Like other Chionea species, adults are active during winter months and are adapted to cold environments, though specific biological details for C. obtusa remain largely unstudied.
Chionea scita
snow crane fly, snow fly
Chionea scita is a wingless crane fly native to North America, notable for its winter activity and ability to walk on snow at temperatures as low as 14°F. Adults emerge between September and February, with peak activity in November and December. The species is commonly found in the northeastern United States and Canada, extending south to Georgia and Tennessee. Both sexes are yellow-brown, hairy, and spider-like in appearance, with body lengths of 5–8 mm.
Chionea stoneana
snow fly
Chionea stoneana is a wingless crane fly species in the family Limoniidae, commonly known as a 'snow fly.' Adults are active during winter months and are frequently observed crawling on snow surfaces. The species occurs in the central United States, ranging from Minnesota and Indiana south to Kansas, Oklahoma, and Missouri. Like other members of its genus, it possesses physiological adaptations for cold tolerance, including glycerol in its body fluids that acts as an antifreeze.
Chordeumatida
Sausage Millipedes, Spinning Millipedes
Chordeumatida is a large order of millipedes containing over 1,100 species, commonly known as sausage millipedes or spinning millipedes. Members of this order are distinguished by their teloanamorphic development—adding segments through molts until reaching a fixed adult number, after which molting ceases. They are notable for possessing spinnerets on their telsons that produce silk used to construct protective chambers for molting and egg-laying. The order exhibits considerable morphological diversity, with species ranging from 3.5 to 42 mm in length and displaying both cylindrical and flat-backed body forms.
Cicurina
cave meshweaver
Cicurina is a genus of small spiders commonly known as cave meshweavers, first described by Anton Menge in 1871. The genus has undergone multiple family reassignments, most recently placed in the family Cicurinidae in 2023. Species exhibit considerable size variation, with some measuring under 2 mm and others exceeding 13 mm. Many species are specialized cave dwellers (troglobites), including several federally endangered species in the United States.
Cirolanides texensis
Cirolanides texensis is a subterranean isopod species endemic to Texas. It belongs to the family Cirolanidae, a group of predominantly aquatic isopods that includes many cave-dwelling species. The species was described in 1896 by Benedict and is known from limited observations in karst groundwater systems.
Cladonychiidae
cladonychiid harvestmen
A small family of harvestmen (suborder Laniatores) comprising approximately 33 described species. Body length ranges from under two to about four millimeters. Members possess robust, spined pedipalps and relatively short legs, though the second pair may reach two centimeters. Coloration varies from reddish brown to dark brown in surface-dwelling species to pale yellow in cave-dwelling forms.
Coecobrya
Coecobrya is a genus of springtails (Collembola: Entomobryidae) characterized by pronounced troglomorphic adaptations in cave-dwelling species. The genus includes both surface and subterranean species, with Thai cave species exhibiting the most extreme troglomorphy known for Collembola in Southeast Asia. Many species display elongated antennae, legs and furca, reduced pigmentation, and eye loss. The genus has been recorded from caves in Thailand, South Africa, and other regions, with molecular studies supporting species discrimination using COI, 16S rDNA and 28S rDNA markers.
Coecobrya tenebricosa
Coecobrya tenebricosa is a cave-dwelling springtail species in the family Entomobryidae. It belongs to the tenebricosa-group, characterized by the absence of eyes, an unguis with one unpaired median tooth, and a manubrium lacking smooth chaetae. The species has been recorded from multiple disjunct regions including the Caribbean mainland, Europe, Hawaii, Macaronesia, and the Mediterranean.
Conotylidae
Conotylidae is a family of millipedes in the order Chordeumatida, containing approximately 19 genera and at least 60 described species. Adult members possess 30 body segments, counting the collum as the first and the telson as the last. The family exhibits its highest diversity in northwestern North America, where five of six subfamilies and ten of fourteen previously described genera occur. Several species are troglobiotic, restricted to cave environments, and some are considered climatic relicts from the Pleistocene.
Copepoda
copepods
Copepods are small aquatic crustaceans and one of the most abundant and diverse multicellular organisms on Earth. They occupy nearly every aquatic habitat, from marine plankton to deep ocean floors, freshwater lakes, groundwater systems, and even moist terrestrial environments such as leaf litter and bromeliad phytotelmata. The group includes free-living forms as well as highly modified parasites. Copepods are fundamental components of aquatic food webs, serving as critical prey for fish, whales, and other marine life, while also contributing to nutrient cycling and carbon sequestration through the biological pump.
Corydioidea
Sand and Cave Cockroaches
Corydioidea is a superfamily of cockroaches (order Blattodea) containing two extant families: Corydiidae (sand cockroaches) and Nocticolidae (cave cockroaches). Together these comprise approximately 50 genera and 250 species. The superfamily also includes two extinct families: Liberiblattinidae and Manipulatoridae from the Cretaceous. Molecular dating places the origin of crown Corydioidea at the Triassic–Jurassic boundary.
Crumomyia
Crumomyia is a genus of small flies in the family Sphaeroceridae, commonly known as lesser dung flies. Species in this genus have been documented from caves in Europe, including a troglophilous population in the Czech Republic that shows morphological adaptations to subterranean life. The genus is distributed across northern and central Europe, with records from Denmark, Norway, and Sweden.
Cyphophthalmi
Mite Harvestmen
Cyphophthalmi is a suborder of harvestmen (Opiliones) comprising six families grouped into three infraorders: Boreophthalmi, Scopulophthalmi, and Sternophthalmi. Adults range from 1 to 7 mm in length with relatively short legs compared to other harvestmen. The suborder is characterized by unique morphological features including elevated cone-shaped ozophores, a spermatopositor instead of a true penis in males, and a completely open gonopore lacking a genital operculum. Many species are eyeless and inhabit leaf litter or caves. Cyphophthalmi represents one of two major lineages of harvestmen, with the other lineage (Phalangida) containing Laniatores, Dyspnoi, and Eupnoi.
Derolathrus
Jacobson's beetles
Derolathrus is a genus of minute beetles in the family Jacobsoniidae, containing 12 described species. The genus includes both extant and extinct species, with fossil records from Cretaceous amber deposits in Myanmar and France. Several species exhibit troglomorphic adaptations, including reduced or absent eyes. The genus has a disjunct global distribution spanning tropical and subtropical regions.
Derolathrus cavernicolus
Jacobson's beetle
Derolathrus cavernicolus is a small beetle in the family Jacobsoniidae, first described from continental North America in 2010. The species is cavernicolous, inhabiting caves and forested habitats in Florida and the Caribbean. It represents the first record of the family Jacobsoniidae for North America. Some populations may have been introduced through horticultural trade.
Dichoxenus
Dichoxenus is a genus of broad-nosed weevils in the family Curculionidae. A 2024 taxonomic revision recognized 25 species, including 17 newly described from Mexico and the southern United States. The genus was expanded through synonymy of Anametis and transfer of several species from other genera. Most species are nocturnal and associated with vegetation, though some occur in leaf litter and three species are known or suspected to be cave-dwelling.
Diplura
Two-pronged Bristletails
Diplura is an order of small, wingless, eyeless hexapods within the class Entognatha, characterized by a distinctive pair of caudal appendages (cerci) that give them their common name "two-pronged bristletails." The group comprises approximately 800 described species worldwide, ranging from 2 to 50 mm in length, with some species reaching up to 8 cm. They inhabit moist soil, leaf litter, humus, and caves across all continents except Antarctica. Diplurans possess concealed mouthparts (entognathous), long bead-like antennae, and the ability to autotomize their cerci when threatened.
Dorypteryx
cave barklice
Dorypteryx is a small genus of cave barklice in the family Psyllipsocidae, containing at least four described species. The genus has a notably wide geographic distribution spanning five biogeographic realms: West Palaearctic, Afrotropical, Australian, Nearctic, and Neotropical, with a 2009 discovery extending its range to China and the Oriental realm for the first time. Species occupy cave and domestic habitats. The genus was taxonomically revised by Lienhard in 1977, who synonymized the monotypic genus Dolopteryx with Dorypteryx.
Dorypteryx domestica
cave barklouse
Dorypteryx domestica is a small psocid, commonly known as the cave barklouse, in the family Psyllipsocidae. Originally described as Dolopteryx domestica from Zimbabwe in 1958, it was later transferred to Dorypteryx by Lienhard in 1977. The species has a remarkably broad geographic distribution spanning Africa, Europe, Northern Asia, and North America, and has been recorded from domestic as well as cave habitats.
Eidmannella
Eidmannella is a genus of scaffold web spiders (family Nesticidae) established by Roewer in 1935. The genus contains eight described species, including the invasive Eidmannella pallida, which has demonstrated significant invasive potential and ecological concern. Species in this genus are associated with both surface and subterranean habitats.
Eidmannella pallida
Pallid cave spider
Eidmannella pallida is a scaffold-web spider in the family Nesticidae with native distribution in North America and established invasive populations across multiple global regions. The species has been introduced to Pacific Islands, the Galápagos Islands, Macaronesia, Spain, Japan, and Italy, where it demonstrates high invasiveness potential. It readily establishes permanent populations in anthropogenic habitats including vineyards, annual crop fields, and olive groves, and shows particular tendency to exploit vulnerable subterranean ecosystems such as caves.
Emesa
thread-legged bugs
Emesa is a small genus of thread-legged bugs (subfamily Emesinae) in the assassin bug family Reduviidae. The genus was established by Fabricius in 1803 and contains only four described species. Members of this genus share the characteristic elongated, slender bodies and extremely long legs typical of Emesinae.
Emesinae
Thread-legged Bugs
Emesinae, commonly known as thread-legged bugs, are a subfamily of assassin bugs (Reduviidae) distinguished by their exceptionally slender body form. They are predatory insects that walk on their mid and hind legs while using their raptorial front legs to capture prey. The subfamily contains approximately 90 genera and 900 described species, with greatest diversity in tropical regions, particularly Africa. Some groups specialize on spiders as prey. Molecular phylogenetic analyses have questioned the monophyly of Emesinae, suggesting the group may be polyphyletic with respect to Saicinae and Visayanocorinae.
Emesini
thread-legged bugs
Emesini is a tribe of thread-legged bugs (Reduviidae: Emesinae) characterized by extremely slender bodies and elongated legs. The tribe contains multiple genera distributed worldwide, with some species exhibiting specialized cave-dwelling habits. Members of this tribe include both surface-dwelling and cavernicolous species, with documented arachnophilous behavior in several taxa.
Entomobrya zona
Rocky Mountain Springtail
Entomobrya zona, commonly known as the Rocky Mountain springtail, is a small springtail species endemic to the Rocky Mountains and known from three caves in the Grand Canyon. Adults reach approximately 2 mm in length and are characterized by tan coloration with black markings, including a distinctive wide dark band running down the center of the abdomen. The species occurs at elevations from 1,700 to over 3,000 meters in arid environments and coniferous forests. It is frequently found in subterranean habitats, where it is considered a troglophile.
Entomobryidae
slender springtails
Entomobryidae, commonly known as slender springtails, is a large family of springtails (Collembola) containing over 1700 described species. Members are characterized by an enlarged fourth abdominal segment, a well-developed furcula (springing organ), and often possess prominent body scales that can produce striking coloration including blue, red, purple, or white patterns. The family includes both scaled and scale-less forms, with the latter frequently captured in pitfall traps globally. Many species are relatively large for springtails, reaching 2 mm or more in length.
Euhadenoecus fragilis
Tawney's Cave Cricket, tawneys cave cricket
Euhadenoecus fragilis is a species of camel cricket in the family Rhaphidophoridae. It was described by Hubbell in 1978. The species is known from cave environments in North America, with documented occurrences in Virginia. Like other members of the family Rhaphidophoridae, it is wingless and adapted to subterranean habitats.
Euhadenoecus insolitus
McCluney Cave Cricket, Highland Rim Crevice Cricket
Euhadenoecus insolitus is a species of camel cricket in the family Rhaphidophoridae, described by Hubbell in 1978. Populations exhibit flexible reproductive strategies, with some reproducing sexually and others through parthenogenesis. The species regularly forages outside cave habitats during warmer months but remains cave-bound in winter.
Geophilus
Compost Centipedes
Geophilus is a large genus of soil centipedes in the family Geophilidae, with approximately 140 species. The genus has a Holarctic distribution and exhibits considerable morphological diversity, with body lengths ranging from under 1 cm to over 7 cm and leg pair counts varying from 29 to 89. Several species have adapted to specialized habitats, including deep cave environments. The genus is characterized by distinctive structural features of the head, forcipules, and trunk segments.
Glomeridae
pill millipedes
Glomeridae is a family of pill millipedes in the order Glomerida, comprising over 300 species distributed among approximately 30 genera. Members are characterized by their ability to conglobate (roll into a complete sphere) as a defensive mechanism. The family has a primarily Palearctic distribution with significant diversity in Southeast Asia, and includes both surface-dwelling and cavernicolous species. Many species remain undescribed, particularly in tropical regions.
Grylloblatta chirurgica
Mount Saint Helens Grylloblattid, Mount Saint Helens grylloblatid
Grylloblatta chirurgica is a species of ice crawler endemic to southwestern Washington state, specifically associated with high-elevation habitats and ice caves near Mount St. Helens in Skamania County. Described by Gurney in 1961, it is one of the rarest and most geographically restricted members of the relict order Notoptera (Grylloblattodea). The species persists in cold, stable microhabitats including glacial ice fields and subterranean ice formations. Its extremely limited distribution and specialized habitat requirements make it vulnerable to environmental change.
Grylloblattidae
ice crawlers, icebugs, rock-crawlers
Grylloblattidae, commonly known as ice crawlers or icebugs, is a family of wingless, cold-adapted insects representing the sole living family of the order Grylloblattodea. These relict insects inhabit extreme cold environments including glacier margins, alpine snowfields, caves, and subalpine forests across disjunct regions of the Holarctic. With approximately 35 extant species in six genera, they exhibit narrow physiological temperature tolerances and are considered endangered due to climate warming and habitat specificity.
Hadenoecus opilionides
Tennessee cave cricket
Hadenoecus opilionides, commonly known as the Tennessee cave cricket, is a camel cricket species described by Hubbell in 1978. It belongs to the family Rhaphidophoridae, a group of wingless crickets specialized for life in dark, humid environments. The species is known from two recognized subspecies: H. o. australis and H. o. opilionides. Records indicate it occurs in Tennessee and broader North America.
Hadziidae
Hadziidae is a family of amphipod crustaceans established by S. Karaman in 1943. Members are taxonomically difficult to distinguish from the closely related family Melitidae. The family includes both marine and freshwater-dwelling species, with some lineages having colonized subterranean habitats.
Haplophthalmus danicus
Spurred Ridgeback, terrestrial cave isopod
Haplophthalmus danicus is a small woodlouse species in the family Trichoniscidae, commonly known as the spurred ridgeback or terrestrial cave isopod. Native to Europe and parts of Asia, it has been introduced to North America, where it has become well established in terrestrial communities since European settlement. The species comprises seven recognized subspecies across its native range. It is frequently observed in cave and subterranean habitats, reflecting its common name.
Heleomyzidae
Sun flies, Heleomyzid flies
Heleomyzidae is a family of small to medium-sized flies in the order Diptera, comprising over 740 described species in approximately 76 genera. The family is distributed worldwide, with the greatest diversity in the Holarctic region. Adults are frequently observed at lights in early spring and late fall. Larval ecology is diverse, with many species associated with decaying organic matter, fungi, carrion, or bird nests.
Heteraphorura
Heteraphorura is a genus of springtails in the family Onychiuridae, first described by Bagnall in 1948. As a member of the tribe Hymenaphorurini, it belongs to a group of euedaphic (deep soil-dwelling) Collembola characterized by reduced or absent eyes and elongated body forms. The genus has been recorded across multiple continents including Europe, Mediterranean regions, northern Eurasia, and parts of North America.
Heterelmis
riffle beetles
Heterelmis is a genus of aquatic beetles in the family Elmidae, commonly known as riffle beetles. The genus includes several described species, with Heterelmis comalensis being particularly notable as an endangered species endemic to spring systems in Texas. Members of this genus are fully aquatic, inhabiting oxygen-rich flowing water environments where they feed on microbial biofilms. Some species have reduced or non-functional wings, limiting their dispersal ability and making them vulnerable to habitat degradation.
Hubbardia pentapeltis
short-tailed whipscorpion
Hubbardia pentapeltis is a species of short-tailed whipscorpion in the family Hubbardiidae, first described by Cook in 1899. It belongs to the order Schizomida, a small group of arachnids characterized by their compact bodies and reduced flagellum. The species is known from North America and has been documented in citizen science observations.
Hypochilus bonneti
lampshade weaver
Hypochilus bonneti is a species of lampshade spider (family Hypochilidae) first described by Gertsch in 1964. It is one of several species in the genus Hypochilus, which are known for their distinctive flat, circular webs that resemble lampshades. The species occurs in the United States, though specific details about its biology and ecology remain poorly documented.
Hypochilus kastoni
Hypochilus kastoni is a species of lampshade spider in the family Hypochilidae, described by Norman Platnick in 1987. It is one of several species in the genus Hypochilus, a group of spiders notable for their distinctive web architecture and relictual distribution in North America. The species is known from the western United States, where it inhabits rocky habitats. Like other Hypochilus species, it constructs characteristic flat, circular webs with a conical retreat, resembling a lampshade in appearance.
Hypogastrura
snow fleas
Hypogastrura is a large genus of springtails in the family Hypogastruridae, comprising at least 150 described species with a cosmopolitan distribution. The genus includes the well-known "snow fleas" such as Hypogastrura nivicola, which are conspicuous on snow surfaces in winter. Members are small, typically 1–3 mm, with the characteristic springtail body plan including a furcula for jumping and a ventral collophore. The genus occupies diverse habitats from Arctic tundra to caves and forest floors.
Ischyropsalididae
Ischyropsalidid Harvestmen
Ischyropsalididae is a family of harvestmen (Opiliones) comprising 35 described species across three genera: Acuclavella (thorn harvestmen of North America), Ceratolasma, and Ischyropsalis (predominantly European). The family exhibits a disjunct distribution spanning Europe and western North America. Several species are troglophilic, inhabiting cave systems with documented adaptations to subterranean environments including seasonal activity patterns and microhabitat specialization.
Jacobsoniidae
Jacobson's beetles
Jacobsoniidae is a small family of minute beetles within the superfamily Staphylinoidea, comprising three extant genera (Derolathrus, Sarothrias, Saphophagus) and approximately 28 described species. Adults and larvae inhabit cryptic microhabitats including leaf litter, rotting wood, fungal fruiting bodies, bat guano, and caves. The family exhibits remarkable morphological stasis since the Cretaceous, with fossil records from Cretaceous amber of Myanmar and France, Eocene Baltic amber, and Holocene copal. Members are among the smallest beetles, measuring 0.7–2.1 mm, and are exceptionally rare in collections.
Keroplatini
Keroplatini is a tribe of fungus gnats within the family Keroplatidae (Diptera). The tribe includes the genus Chetoneura, which was formally transferred from Orfelia to Keroplatini based on phylogenetic analysis. At least one member, Chetoneura shennonggongensis, is a cave-dwelling species with documented larval biology involving silk construction for prey capture.
Laemostenus
Laemostenus is a genus of ground beetles (Carabidae) comprising nearly 200 species distributed across all continents except Antarctica. Species range from 8 to 28 mm in length. Many exhibit dark coloration with blue or purple metallic sheen, while subterranean and cave-dwelling species show depigmentation, reduced eyes, and lighter coloration. The genus includes both surface-dwelling and hypogean (subterranean) species, with several subgenera recognized.
Leptonetidae
cave spiders
Leptonetidae is a family of small, primitive haplogyne spiders first described by Eugène Simon in 1890. The family comprises approximately 22 genera and 400 species, though taxonomic boundaries have been revised recently with elevation of Archoleptonetinae to family rank (Archoleptonetidae). Leptonetids are characterized by their small size (2-5 mm), reduced eye number, and adaptation to dark, moist microhabitats. They represent a relict fauna with origins dating to the Cretaceous period and exhibit complex biogeographic patterns across the Holarctic.
Liocranidae
sac spiders
Liocranidae is a family of araneomorph spiders first described by Eugène Simon in 1897. They are commonly referred to as 'sac spiders' due to their habit of constructing silk retreats. The family contains 35 genera and approximately 357 species as of January 2026. The holarctic genus Agroeca is the best-known member, while many other genera remain poorly studied and lack formal diagnoses. Recent taxonomic work has significantly expanded the family, including the description of numerous new species from China, Vietnam, and other regions.
Lithobiomorpha
Stone Centipedes
Lithobiomorpha, commonly known as stone centipedes, are an order of anamorphic centipedes characterized by a mature segment count of 15 trunk segments. They lack compound eyes, possessing instead simple ocelli or no eyes in some subterranean species. The order includes two families: Henicopidae and Lithobiidae. Members are primarily found in forest litter and soil habitats across temperate regions worldwide, with significant diversity in China and Europe.
Lithobius
stone centipedes, common centipedes, brown centipedes, typical stone centipedes
Lithobius is a large genus of centipedes in the family Lithobiidae, containing over 500 species and numerous subspecies. Adults possess 18 body segments and 15 pairs of legs, with body lengths ranging from approximately 2–5 cm. The genus was erected by William Elford Leach in 1814 and serves as the type genus for the family Lithobiidae. These centipedes are primarily nocturnal predators found in soil, leaf litter, and beneath stones or bark across temperate regions worldwide.
Lithobius peregrinus
Peregrine Stone Centipede
Lithobius peregrinus is a stone centipede species first described in 1880 by Austrian myriapodologist Robert Latzel. The species has a cosmopolitan distribution with type locality in Dalmatia, Croatia. A 2022–2024 study of a troglophilic population in Gaura cu Muscă Cave, Romania documented significant morphological variations, asymmetries, and teratological features across 39 specimens. The species exhibits close water affinity and has been recorded in both surface and subterranean habitats.
Megacina
Megacina is a genus of armoured harvestmen in the family Phalangodidae, established by Ubick & Briggs in 2008. The genus contains at least four described species, all found in western North America. These species are characterized by heavily sclerotized body armor typical of the family. The genus was erected based on morphological distinctions from related phalangodid genera.
Meta dolloff
Dolloff Cave Spider
Meta dolloff, commonly known as the Dolloff Cave Spider, is a rare spider species endemic to California. It belongs to the family Tetragnathidae, a group characterized by elongated bodies and long jaws. The species is considered among the rarest spiders in North America, with limited observations documented.
Metellina
Autumn Spider
Metellina is a genus of orb-weaving spiders in the family Tetragnathidae, distributed primarily across Eurasia with two species in North America. The genus includes sixteen species as of 2025, with M. segmentata being the most abundant orb-weaving spider in Germany and introduced to Canada. Metellina spiders construct webs low in vegetation and are commonly known as Autumn Spiders. Some researchers have proposed placing this genus in a distinct family, Metidae.
Mezium
spider beetles
Mezium is a genus of spider beetles (subfamily Ptininae) with a global distribution concentrated in two main regions: the western Mediterranean from the Iberian Peninsula to Morocco and the Canary Islands, and central and southern Africa. Species in this genus are primarily cave-dwelling, feeding on animal feces and bat guano, though several have adapted to human-made structures such as barns and chicken coops. The genus includes notable species such as Mezium affine (shiny spider beetle) and Mezium americanum (American spider beetle).
Micropholcus
cellar spiders
Micropholcus is a genus of cellar spiders (Pholcidae) characterized by long legs and relatively fragile bodies. It is one of only two pholcid genera with both Old and New World distributions, though morphological and ecological differences exist between geographic groups. The genus currently contains at least 29 species, with major taxonomic revisions in 2014 (transfers from Leptopholcus) and 2024 (description of twelve new Old World species). The type species M. fauroti has a pantropical distribution and has been introduced globally.
Monopis crocicapitella
Pale-backed clothes moth, Bird-nest moth, Bird Nest Moth
A small tineid moth with a nearly cosmopolitan distribution, first described from the eastern United States. Adults have a wingspan of 10–16 mm. The species has been documented in cave environments and serves as a host for the parasitoid wasp Apanteles carpatus. Its capability to infest human dwellings remains unknown.
Neelidae
Neelidae is a family of minute springtails in the order Neelipleona, comprising at least four genera and more than 30 described species. Members average around 500 μm in length and possess globular bodies superficially resembling those of Symphypleona, with relatively long legs and a well-developed furca. Molecular phylogenetic data places Neelidae as a basal group to all other Collembola, despite earlier morphological hypotheses linking them closely to Symphypleona. The family has worldwide distribution with records from Gondwanan regions, caves, and various terrestrial habitats.
Neelipleona
Neelipleona is an order of minute hexapods within the class Collembola (springtails). Members are characterized by the complete absence of eyes, a trait distinguishing them from most other springtail groups. The group is primarily represented by the family Neelidae and includes genera such as Megalothorax and Spinaethorax. Many species exhibit troglomorphic adaptations, including elongated appendages and reduced pigmentation, associated with cave-dwelling habits. The taxonomic rank of Neelipleona remains debated, with some authorities treating it as a suborder of Symphypleona or placing it within Entomobryomorpha.
Neelus
Neelus is a genus of springtails (Collembola) in the family Neelidae, established by Folsom in 1896. The genus contains both surface-dwelling and troglobiotic (cave-restricted) species. Several species exhibit troglomorphic adaptations including elongated unguis (claws), larger body size, and elongated antennal sensilla. The genus has a broad geographic distribution spanning Europe, North America, and Asia, with notable cave-dwelling diversity in the Balkans.
Nemastomatidae
Nemastomatid Harvestmen
The Nemastomatidae are a family of harvestmen (Opiliones: Dyspnoi) comprising approximately 170 described species in 16 extant genera. The family is divided into two subfamilies with disjunct distributions: Nemastomatinae in Europe, North Africa, and western Asia, and Ortholasmatinae in western North America and eastern Asia. Members are characterized by variable body size (1–6 mm) and often possess elongated, thread-like pedipalps. The family is monophyletic and likely sister to the Dicranolasmatidae and Trogulidae.
Neobisiidae
neobisiid pseudoscorpions
Neobisiidae is a family of pseudoscorpions comprising approximately 550-750 species across 32-34 genera, distributed across Africa, the Americas, and Eurasia. Members are small arachnids ranging from 1 to 5 mm in body length, with body colors varying from reddish or dark brown through olive green to yellow or creamy white. The family includes both surface-dwelling and cave-dwelling species, with troglobitic species often exhibiting eye reduction or loss. Several genera, notably Stenohya, exhibit pronounced sexual dimorphism in pedipalp morphology.
Neobisioidea
Neobisioidea is a superfamily of pseudoscorpions established by Chamberlin in 1930. It contains seven families, including Gymnobisiidae, Hyidae, Neobisiidae, Parahyidae, and Syarinidae. Members of this superfamily exhibit diverse ecological specializations, with some species restricted to moist leaf litter habitats and others adapted to subterranean cave environments. Several families show Gondwanan distribution patterns and high levels of short-range endemism.
Neocarus
Neocarus is a genus of rare, relatively large mites in the family Opilioacaridae, characterized by primitive traits including six pairs of eyes and abdominal segmentation. Species in this genus are primarily associated with subterranean habitats in Brazil, including caves and ferruginous geosystems. Multiple new species have been described from Minas Gerais state, where they occur in both epigean and hypogean environments.
Neogoveidae
Neogoveid Harvestmen
Neogoveidae is a family of small, eyeless harvestmen (Cyphophthalmi) distributed across tropical regions of West Africa and the Neotropics. Members range from 1 to 4.5 mm in body length and exhibit distinctive morphological features including a heavily granulated dorsal scutum, laterally projecting ozophores, and variable adenostyle morphology. The family shows substantial undescribed diversity, with many species awaiting formal description.
Nesticus furtivus
Crystal Caverns Cave Spider
Nesticus furtivus is a small cave-dwelling spider endemic to a single cave system in Tennessee. It belongs to the family Nesticidae, a group commonly known as cave spiders or scaffold web spiders. The species has been documented only from Raccoon Mountain Caverns (formerly Crystal Caverns) near Chattanooga, making it one of the most geographically restricted spider species in North America. Its specific epithet 'furtivus' refers to its secretive, hidden lifestyle in subterranean habitats.
Oecleini
Oecleini is a tribe of planthoppers (Hemiptera: Cixiidae) established by Muir in 1922. Members exhibit distinctive wing venation patterns, including a trifid anterior MP branch in forewings and I-type hindwing venation with complete fusion of MP3+4 with CuA1. Some species possess subterranean adaptations, including a double-grasping coxo-femoral and femoro-tibial system in nymphs for clinging to roots. The tribe includes economically significant species investigated as potential vectors of palm phytoplasmas.
Oncopodura
Oncopodura is a genus of springtails (Collembola) in the family Oncopoduridae, established by Carl & Lebedinsky in 1905. The genus contains multiple species distributed across tropical and subtropical regions including Amazonia, the Andes, the Caribbean, and Southeast Asia. At least one species, O. moghanensis, has been described from subterranean cave habitats in Iran. Species in this genus exhibit distinctive morphological features of the postantennal organ (PAO) and furca that serve as key diagnostic characters.
Oncopoduridae
Oncopoduridae is a family of springtails (Collembola) in the order Entomobryomorpha, established by Carl and Lebedinsky in 1905. The family contains the genus Oncopodura, which includes subterranean species adapted to cave environments. Members of this family are characterized by distinctive morphological features of the postantennal organ (PAO) and furcula that are important for species identification.
Onychiurus
springtails
Onychiurus is a genus of springtails (Collembola) in the family Onychiuridae with cosmopolitan distribution. The genus contains numerous species, including both surface-dwelling forms in forest soils and agricultural fields, as well as specialized cave-dwelling species. Members of this genus have been extensively studied as indicators of soil health and pesticide impacts.
Opilioacarida
Opilioacarida is a small order of mites containing a single family, Opilioacaridae, with approximately 13 genera and 53 valid taxa. These mites are among the largest of their kind (1.5–2.5 mm) and are considered primitive due to retained ancestral traits including six pairs of eyes and abdominal segmentation. Molecular phylogenetics places them within Parasitiformes, though historically they were treated as distinct from both Acariformes and Parasitiformes. The group has a worldwide distribution with notable diversity in the Americas.
Opiliones
harvestmen, harvesters, daddy longlegs, granddaddy longlegs, shepherd spiders
Opiliones is an ancient order of arachnids comprising over 6,650 described species, with estimates suggesting more than 10,000 extant species worldwide. The order includes five suborders: Cyphophthalmi, Eupnoi, Dyspnoi, Laniatores, and Tetrophthalmi. Fossil evidence from 410 million-year-old Devonian deposits demonstrates that harvestmen have remained morphologically conservative since their early evolution. Despite superficial resemblance to spiders, Opiliones represent a distinct arachnid lineage with unique anatomical and behavioral characteristics.
arachnidharvestmandaddy-longlegsancient-lineageomnivorenocturnalgregariouscave-dwellingpaternal-carechemical-defenseautotomymodel-organismconservation-concernvenomlesstracheal-respirationdirect-copulationshort-range-endemictroglobiteaposematiccrypsismimicrythanatosisviscoelastic-adhesiveanurophagyvertebrate-predatorOrfelia fultoni
Foxfire Fly, dismalites
Orfelia fultoni is the only bioluminescent fly species known from North America. The larvae, commonly called 'dismalites' or 'glowworms,' produce the bluest light (~460 nm) of any studied bioluminescent insect. Larvae are carnivorous predators that construct sticky webs along stream banks and in caves, using paired bioluminescent lanterns to lure flying prey. Adults are non-feeding and short-lived. The species was discovered in 1940 near Glenville, North Carolina by B.B. Fulton and described by Elizabeth Gault Fisher.
Paederinae
Tomcat
Paederinae is a subfamily of rove beetles (Staphylinidae) containing three tribes: Lathrobiini, Paederini, and Pinophilini. The subfamily is notable for containing the genus Paederus and related genera that produce pederin, a potent vesicant toxin in their haemolymph that causes Paederus dermatitis in humans. The subfamily exhibits diverse ecological adaptations including myrmecophily, troglobitic cave-dwelling, and intertidal lifestyles. Over 36 genera and 436 species occur in North America alone, with global distribution across multiple biogeographic regions.
Palpigradi
microwhip scorpion, palpigrade, micro whipscorpion
Palpigradi is an order of minute arachnids, commonly called microwhip scorpions or palpigrades. They are the sister group to Solifugae (camel spiders), measuring 1–3 mm in length. These pale, thin-bodied arachnids inhabit wet tropical and subtropical soils worldwide, living interstitially in moist microhabitats under stones and in caves. They possess a distinctive multi-segmented flagellum that may comprise half the body length. The order contains two families, Prokoeneniidae and Eukoeneniidae, distinguished by the presence or absence of ventral respiratory sacs.
Paradoxosomatidae
flat-backed millipedes
Paradoxosomatidae is the largest family of flat-backed millipedes, containing nearly 200 genera and approximately 975 species as of 2013. It is the sole family in the suborder Paradoxosomatidea. Members are distinguished by dorsal grooves on most body segments and a dumb-bell shaped gonopod aperture in males. The family includes notable groups such as the dragon millipedes of Southeast Asia and the widely introduced greenhouse millipede Oxidus gracilis.
Paraphrynus
whip spider, tailless whip scorpion
Paraphrynus is a genus of whip spiders (order Amblypygi) in the family Phrynidae, distributed from the southwestern United States through Central America and the Caribbean. Most species are endemic to Mexico. These nocturnal arachnids are characterized by extraordinarily long, sensory front legs (antenniform legs) used for navigation and prey detection, and spiny pedipalps for capturing prey. Research has demonstrated remarkable homing abilities in some species, with individuals navigating back to refuges from distances exceeding 10 meters using primarily olfactory cues detected by their antenniform legs rather than vision.
Parobisium
Parobisium is a genus of poorly dispersing pseudoscorpions in the family Neobisiidae. The genus exhibits a disjunct distribution pattern occurring in western North America and eastern Asia (East Asia), but is absent from Europe and central Asia. Phylogenetic evidence indicates ancient vicariance between East Asian and North American lineages rather than recent dispersal events. Many species are troglomorphic and restricted to karst cave systems.
Phalangodidae
Phalangodid Harvestmen
Phalangodidae is a family of small harvestmen in the suborder Laniatores, containing approximately 30 genera and more than 100 described species. Members are characterized by pedipalps armed with prominent spines and body lengths generally under 3 mm. The family is primarily distributed in the Holarctic region, with exceptional diversity in the western Nearctic, particularly California. Several species, especially in the genus Texella, are obligate cave-dwellers exhibiting troglomorphic traits such as depigmentation and reduced eyes.
Pholcidae
cellar spiders, daddy long-legs spiders, carpenter spiders, vibrating spiders, gyrating spiders
Pholcidae is a large family of araneomorph spiders containing over 2,000 species across 94+ genera. Members are commonly known as cellar spiders or daddy long-legs spiders due to their extremely long, thin legs and tendency to inhabit dark, undisturbed spaces. The family exhibits remarkable diversity in habitat use, from caves and tropical forests to human dwellings, with some species showing specialized adaptations including troglomorphism and communal web-sharing. Several species have become globally distributed through human transport, notably Pholcus phalangioides.
Phrurolithidae
Guardstone Spiders
Phrurolithidae is a family of araneomorph spiders commonly known as guardstone spiders. First described by Nathan Banks in 1892, the family was long treated as a subfamily (Phrurolithinae) within Corinnidae until phylogenetic studies established its separate family status. The family currently comprises 27 genera and approximately 421 species. Members are small to medium-sized spiders, predominantly found in the Northern Hemisphere with exceptional diversity in southern China, where many species are endemic to specific mountain localities.
Phrynus marginemaculatus
spotted tailless whip scorpion, Florida tailless whipscorpion
Phrynus marginemaculatus is an amblypygid arachnid native to southern Florida, the Bahamas, Cuba, and Hispaniola. It is the only amblypygid species in the US east of the Mississippi River and the most commonly studied whip spider species. This nocturnal predator possesses extraordinarily elongated first pair of legs adapted as sensory organs for detecting prey, mates, and environmental features in darkness. The species exhibits complex navigational abilities including multisensory configural learning for shelter recognition, and has evolved a plastron enabling underwater breathing for up to 24 hours.
Phrynus operculatus
tailless whipscorpion
A medium-sized tailless whipscorpion (18–22 mm total length) found across much of Mexico. Distinguished by chestnut coloration with reddish tones on the carapace and pedipalps, four anterior spines on the pedipalp trochanter, and specific female gonopod morphology. The species shows considerable morphological variation across its range, suggesting it may represent a species complex.
Pimoidae
Large Hammock-web Spiders
Pimoidae is a small family of araneomorph spiders established by Wunderlich in 1986, closely related to Linyphiidae and sometimes treated as synonymous with that family. As re-circumscribed in 2021, it is monophyletic and contains approximately 90 species in two genera, primarily Pimoa and Weintrauboa. Members are commonly known as large hammock-web spiders due to their substantial size relative to linyphiids and their horizontal, net-like webs. The family has a fragmented relictual distribution across the Pacific coast of North America, the Cantabrian Mountains of Spain, the European Alps, and the Himalayas and adjacent regions of Asia.
Platypezidae
Flat-footed Flies
Platypezidae is a family of small true flies (Diptera) comprising over 250 species worldwide. Adults are commonly known as flat-footed flies due to their characteristically modified tarsal segments, particularly in males. The family is primarily associated with woodland habitats where larvae develop as fungivores. Adults exhibit distinctive swarming behavior for mating and are frequently observed performing rapid, erratic movements on vegetation. The family was formerly broader in circumscription, with Opetiidae and some genera now placed in Atelestidae removed based on phylogenetic evidence.
Porrhomma convexum
Porrhomma convexum is a species of sheetweb spider in the family Linyphiidae, characterized by its small size and association with cave and subterranean habitats. The species was described by Westring in 1851 and has a broad Holarctic distribution spanning North America, Europe, and Asia. Like other members of its genus, it exhibits adaptations to dark environments including reduced pigmentation and eye size. The species constructs sheet webs typical of its family.
Prionoglarididae
Large-winged Barklice
Prionoglarididae is a family of small, winged insects in the order Psocodea, commonly known as barklice or booklice. The family contains approximately 9 genera and over 20 described species distributed across Europe, Asia, Africa, and North America. Members are characterized by reduced or simplified lacinia (mouthpart structures) in adults and highly specialized male genitalia. The genus Neotrogla is notable for exhibiting sex-reversed genitalia, with females possessing an intromittent organ (termed a gynosome) and males having vagina-like structures. Most species inhabit cave environments.
Procambarus
crayfish, crawfish, crawdad
Procambarus is a genus of freshwater crayfish in the family Cambaridae, native to North and Central America. The genus contains approximately 160 species in 16 subgenera, making it one of the most species-rich crayfish genera. It includes both widespread surface-dwelling species and numerous troglobitic (cave-dwelling) species. The marbled crayfish (marmorkrebs), a parthenogenetic form, is also classified within this genus. Several species, particularly P. clarkii (red swamp crayfish), have been introduced globally and are recognized as invasive species with significant ecological and economic impacts.
Prokoeneniidae
microscorpions, microwhip scorpions
Prokoeneniidae is a family of microscorpions (order Palpigradi) established by Condé in 1996. The family contains at least two genera—*Prokoenenia* and *Triadokoenenia*—with approximately seven described species. These minute arachnids are among the least studied of all arachnid orders, reflecting their cryptic lifestyle and small size.
Protaphorura
Protaphorura is a genus of springtails (Collembola) in the family Onychiuridae, established by Absolon in 1901. The genus contains numerous species distributed across the Palearctic region, with particular diversity in southern Siberia and the Far East of Russia. Several species are obligate cave-dwellers (troglobionts), exhibiting specialized adaptations to subterranean environments. The genus is taxonomically well-studied, with identification keys available for over 85 Palearctic species based on morphological characters including pseudocellar formulae, postantennal organ structure, and chaetotaxy.
Pseudanophthalmus cerberus cerberus
Pseudanophthalmus cerberus cerberus is a subspecies of troglobitic ground beetle in the family Carabidae. It belongs to a genus of small, eyeless beetles adapted to life in caves. The subspecies was described by Barr in 1985 and is currently accepted as valid. Like other members of Pseudanophthalmus, it is likely restricted to subterranean habitats in the eastern United States.
Pseudocellus dorotheae
hooded tickspider
Pseudocellus dorotheae is a species of hooded tickspider in the order Ricinulei, first described from Texas in 1939. Ricinuleids are a small, reclusive order of arachnids characterized by a retractable hood (cucullus) covering the mouthparts. This species represents one of the few described members of the genus Pseudocellus in North America. Like other ricinuleids, it is poorly known due to its cryptic habits and limited collection records.
Pseudogarypidae
Pseudogarypid Pseudoscorpions
Pseudogarypidae is a small family of pseudoscorpions within the superfamily Feaelloidea. The family comprises two extant genera—Pseudogarypus and Neopseudogarypus—with most recent species distributed in western North America. A single extant species, Neopseudogarypus scutellatus, is endemic to Tasmania, representing a notable disjunct distribution. The family also includes several fossil species preserved in Baltic amber from the Eocene.
Pseudorypteryx
Pseudorypteryx is a monotypic genus of cave-dwelling barklice in the family Psyllipsocidae, erected by García-Aldrete in 1984. The genus contains a single described species, Pseudorypteryx mexicana. Members of this genus are troglobitic, meaning they are specialized for life in cave environments.
Pseudoscorpiones
pseudoscorpions, false scorpions, book scorpions
Pseudoscorpions are tiny arachnids, most under 5 mm in length, superficially resembling scorpions but lacking a stinger and elongated tail. They are among the oldest terrestrial colonizers, with fossils dating to the Middle Devonian (ca. 390 million years ago). Despite their ancient lineage, they exhibit remarkable morphological stasis, with even Devonian fossils appearing modern. Most species inhabit concealed microhabitats such as beneath bark, in leaf litter, soil, caves, or mammal nests, making them seldom encountered despite being fairly common. They are predatory, seizing small invertebrate prey with venomous pincer-like pedipalps.
Psilochorus apicalis
Psilochorus apicalis is a species of cellar spider in the family Pholcidae, first described by Banks in 1921. It is a small, long-legged spider endemic to the United States. Like other pholcids, it constructs irregular, tangled webs in sheltered locations. The species is part of a genus containing approximately 20 described species, most occurring in the Americas.
Psilochorus californiae
Psilochorus californiae is a species of cellar spider in the family Pholcidae. It was described by Chamberlin in 1919. The species occurs in the southwestern United States and Mexico. Like other pholcids, it constructs irregular, three-dimensional webs in dark, sheltered locations.
Psilochorus simoni
Wine Cellar Spider
Psilochorus simoni is a cellar spider in the family Pholcidae, native to subtropical America and introduced to Europe, Turkey, New Zealand, and Australia. The species is commonly known as the "Wine Cellar Spider" due to its historical association with wine cellars, though it has become established in garden centres and greenhouses. It constructs dome-shaped webs and has been recorded from cave environments in Europe, including Slovenia's Postonjska jama, where it shows morphological adaptations to subterranean life.
Psocathropos
Psocathropos is a genus of small, wingless psocids (booklice) in the family Psyllipsocidae. Members of this genus are troglophilic or troglobitic, often found in caves and other subterranean habitats. The genus was established by Ribaga in 1899 and contains species distributed across multiple continents including North America, the Caribbean, and South Asia.
Psyllipsocidae
Cave Barklice
Psyllipsocidae is a family of small psocid insects commonly known as cave barklice, comprising approximately 7 genera and more than 70 described species. The family belongs to the suborder Trogiomorpha within the order Psocodea. Members of this family have been recorded across multiple biogeographic realms including West Palaearctic, Afrotropical, Australian, Nearctic, Neotropical, and Oriental regions. Some genera, such as Dorypteryx, exhibit notably wide geographic distributions. Several extinct genera are known from Cretaceous amber deposits.
Psyllipsocus
Psyllipsocus is a genus of cave-dwelling barklice comprising more than 50 described species. Members of this genus inhabit dark, humid microhabitats including caves, rock crevices, and similar subterranean environments. The genus was established by Selys-Longchamps in 1872 and represents one of the most species-rich genera within the family Psyllipsocidae.
Psyllipsocus ramburii
cave barklouse
Psyllipsocus ramburii is a species of cave barklouse in the family Psyllipsocidae, first described by Selys-Longchamps in 1872. It is notable for its exceptionally broad geographic distribution, spanning six continents and numerous oceanic islands. The species belongs to the suborder Trogiomorpha, a group characterized by reduced or absent wings and troglophilic tendencies.
Pyralis manihotalis
Tropical Meal Moth
Pyralis manihotalis is a small pyralid moth with a pan-tropical distribution, described by Achille Guenée in 1854. It is frequently associated with stored products and decaying organic matter, earning it the common name Tropical Meal Moth. The species has been documented in an unusually wide range of habitats, including caves where self-sustaining populations feed on bat guano. Adults are nocturnal and attracted to ultraviolet light.
Pyrophorini
Headlight Beetles
Pyrophorini is a New World tribe of click beetles (Elateridae: Agrypninae) characterized by bioluminescence in both larvae and adults. The tribe comprises approximately 20 genera including Pyrophorus, Ignelater, and Pyrearinus. Members are known for producing light through specialized organs, with larvae associated with phenomena such as 'luminescent termite mounds' and 'luminous canga caves' in South America. The tribe is believed to be monophyletic and is closely related to Anaissini, which contains some but not all bioluminescent species.
Quedius spelaeus
Spelean Rove Beetle
A troglophilic rove beetle found in porcupine dung caves in Nova Scotia, where it functions as the dominant invertebrate predator. The pupal stage was described for the first time from Nova Scotian populations. Late-instar larvae excavate and occupy cavities within dung deposits, pupating in these constructed chambers. The species shows an apparently disjunct distribution pattern in Nova Scotia, possibly reflecting post-glacial colonization from Atlantic refugia.
Rymosia
Rymosia is a genus of fungus gnats (Diptera: Mycetophilidae) in the tribe Exechiini. Species occur in Europe, Russia, Japan, and the Americas. At least one species, Rymosia tolleti, is exclusively associated with cave environments. The genus is part of the Rymosia s. lat. genus group, a phylogenetically cohesive assemblage of genera considered to share plesiomorphic characteristics.
Sabacon
Sabacon is a genus of harvestmen (order Opiliones) comprising the monotypic family Sabaconidae, with approximately 59 species recognized as of 2023. Species in this genus are primarily cave-dwelling or associated with moist, sheltered habitats in temperate and boreal regions of the Northern Hemisphere. The genus exhibits a disjunct distribution pattern with centers in North America (especially the southern Appalachians), Europe (Pyrenees, Alps), and Asia (Altai Mountains, Siberia). Several species have been described recently, indicating ongoing taxonomic discovery.
Schaefferia
Schaefferia is a genus of springtails (Collembola: Poduromorpha: Hypogastruridae) characterized by troglomorphic adaptations in cave-dwelling species. Recent taxonomic work has described highly specialized subterranean species from Iran and Montenegro that exhibit convergent evolution of eyelessness and elaborated sensory structures. The genus demonstrates significant morphological diversification associated with subterranean habitats.
Scoliopteryx
herald moth
Scoliopteryx is a genus of moths in the family Erebidae, established by Ernst Friedrich Germar in 1810. The genus contains two described species, including Scoliopteryx libatrix (the herald moth), which is notable for its troglophilic behavior and cave-dwelling habits during winter. Species in this genus have been studied for their unique ecological associations, including shared hibernacula with insectivorous bats and susceptibility to entomopathogenic fungi.
Scoliopteryx libatrix
Herald Moth, Herald
Scoliopteryx libatrix, commonly known as the herald moth, is a noctuid moth distributed across the Holarctic region. Adults are notable for their distinctive wing patterning and behavior of overwintering in caves, mines, and similar sheltered structures. The species has been documented as a host for entomopathogenic fungi and shares hibernacula with insectivorous bats. Its acoustic sensitivity to bat echolocation frequencies, combined with an absence of evasive flight responses during hibernation, represents an unusual behavioral adaptation.
Scolopocryptopidae
Scolopocryptopid Centipedes
Scolopocryptopidae is a family of blind centipedes in the order Scolopendromorpha, comprising more than 90 species. The family is distinguished from all other centipedes by having exactly 23 pairs of legs—a fixed trait that contrasts with the variable leg counts in other families. Members are eyeless and possess a distinctive gizzard with kinked, pineapple-shaped sieve projections. The family is most diverse in the Neotropical realm, with four recognized subfamilies: Ectonocryptopinae, Kethopinae, Newportiinae, and Scolopocryptopinae.
Scoterpes
Scoterpes is a genus of troglobiotic millipedes in the family Trichopetalidae, order Chordeumatida. Established by Cope in 1872, the genus comprises exclusively cave-dwelling species found in North America. The genus was revised in 2010, with fifteen recognized species including eight newly described taxa. At least two species, S. copei and S. ventus, likely represent superspecies complexes consisting of multiple genetically isolated populations.
Scoterpes sollmani
Scoterpes sollmani is a troglobiotic millipede described by Lewis in 2000 from cave systems in southern Indiana. As a member of genus Scoterpes, it is one of multiple cave-adapted species in this exclusively troglobiotic group. The species belongs to the small family Trichopetalidae within the order Chordeumatida, a group of small-bodied millipedes. No specific morphological details distinguishing S. sollmani from congeners are provided in available sources.
Sicariidae
Sixeyed Sicariid Spiders, recluse spiders, violin spiders, sand spiders, assassin spiders
Sicariidae is a family of haplogyne spiders comprising three genera—Loxosceles, Sicarius, and Hexophthalma—with approximately 177-180 species. Members are characterized by six eyes arranged in three dyads (pairs), a distinctive trait among spiders. The family includes medically significant species such as the brown recluse (Loxosceles reclusa) and six-eyed sand spiders. All genera produce sphingomyelinase D or related tissue-destroying substances in their venom, unique among spiders. The family exhibits diverse ecological strategies: Loxosceles species are synanthropic and found nearly worldwide in warmer regions, while Sicarius and Hexophthalma are specialized desert dwellers with self-burying behavior.
Sinella cavernarum
Cavernicolous springtail
Sinella cavernarum is a species of springtail in the family Entomobryidae, first described by Packard in 1888. The species epithet 'cavernarum' (of caves) suggests a troglophilic or troglobitic lifestyle. As an entomobryomorph springtail, it possesses the characteristic elongated body form and well-developed antennae typical of this group. Very few observations of this species exist in public databases.
Siro
harvestmen
Siro is a genus of cyphophthalmid harvestmen (Opiliones) in the family Sironidae. These small arachnids are characterized by their eyeless condition, elongated bodies, and association with moist microhabitats. The genus was established by Latreille in 1795 and represents one of the early-recognized lineages of the suborder Cyphophthalmi, which diverged from other harvestmen early in the evolutionary history of the order. Species in this genus are distributed primarily in the Mediterranean region and parts of Europe.
Sironidae
Sironid Harvestmen
Sironidae is a family of Cyphophthalmi harvestmen comprising more than 60 described species. It was the first described family of the suborder Cyphophthalmi and remains among the least understood phylogenetically. The family exhibits a predominantly Laurasian distribution, with species concentrated in temperate Europe and the west coast of North America. Monophyly of the family is poorly supported with traditional molecular markers; the Mediterranean genus Parasiro and Japanese genus Suzukielus sometimes branch basally relative to other sironids.
Speleomaster
Speleomaster is a genus of armoured harvestmen (Opiliones: Laniatores) described by Briggs in 1974. The genus contains at least two species, both endemic to subterranean lava tube environments in southern Idaho's Snake River Plain. As members of the family Cryptomastridae, these harvestmen represent a specialized lineage adapted to cave life.
Speleonychia sengeri
Speleonychia sengeri is a troglobitic harvestman (order Opiliones) described by Briggs in 1974. The genus Speleonychia is endemic to cave systems in western North America. As a member of the family Cladonychiidae, this species belongs to a group of small, eyeless, pale-colored arachnids adapted to subterranean environments. Very few observations exist—only five records on iNaturalist—reflecting its restricted habitat and cryptic lifestyle.
Spirostreptida
Spirostreptida is an order of large, cylindrical millipedes containing approximately 1000 described species, making it the third largest order of millipedes. Members are characterized by their elongated bodies with 30 to 90 body rings and generally large size, including the longest known millipedes such as the giant African millipedes of genus Archispirostreptus, which may exceed 30 cm. The order is divided into two suborders, Cambalidea and Spirostreptidea, with most species occurring in tropical and subtropical regions. Spirostreptida are primarily soil-dwelling detritivores, though some species inhabit caves.
Stenancylus
Stenancylus is a genus of true weevils (Curculionidae) established by Casey in 1892. The genus contains nine described species, most described by Wibmer & O'Brien in 1986. Species are distributed across the Americas, with records from Panama, Colombia, and the United States. The genus name derives from Greek roots suggesting narrow or slender form.
Stenasellidae
Stenasellidae is a family of stygobiotic (obligate subterranean aquatic) isopods in the suborder Asellota. The family comprises approximately 10 genera including Stenasellus, Metastenasellus, and Parastenasellus, with species distributed across groundwater habitats in Africa, the Middle East, southern Europe, and Southeast Asia. These crustaceans are exclusively adapted to life in continental underground waters including caves, wells, and interstitial aquifers. Their evolutionary history has been shaped by Quaternary climatic events including aridification in tropical zones and glaciations in temperate regions.
Stenochrus
short-tailed whipscorpions
Stenochrus is a genus of hubbardiid short-tailed whipscorpions (order Schizomida) first described by Ralph Vary Chamberlin in 1922. The genus was historically considered a 'junkyard' taxon containing morphologically disparate species, but integrative systematics using molecular and morphological data has redefined its boundaries. As currently circumscribed, Stenochrus comprises approximately ten species distributed primarily in Mexico, Central America, and the Caribbean. The most widespread species, Stenochrus portoricensis, exhibits exceptional geographic range due to parthenogenetic reproduction and ecological tolerance, with introduced populations established in South America and Europe.
Stenochrus portoricensis
short-tailed whipscorpion, microwhipscorpion
Stenochrus portoricensis is a widely distributed short-tailed whipscorpion (Schizomida: Hubbardiidae) native to the Neotropics and Nearctic regions. The species exhibits exceptional dispersal capability facilitated by parthenogenetic reproduction, enabling establishment in diverse habitats across multiple continents. Molecular studies indicate the species is paraphyletic, with a Mesoamerican origin and multiple independent introductions to Europe and the Caribbean from the Yucatán Peninsula. Sexual populations persist in natural habitats across Cuba, Dominican Republic, Guatemala, Mexico, Nicaragua, and Puerto Rico, while parthenogenetic lineages dominate introduced ranges.
Stygnommatidae
Stygnommatid Harvestmen
Stygnommatidae is a small family of harvestmen (Opiliones) in the infraorder Grassatores, containing approximately thirty described species. These arachnids are characterized by their compact body form, enlarged and armed pedipalps, and relatively short legs. They are primarily litter-dwelling inhabitants of Neotropical forests, with some species adapted to cave environments. The family's monophyly remains disputed among arachnologists.
Stygobromus pecki
Peck's cave amphipod
Stygobromus pecki is a small, eyeless, unpigmented cave-dwelling amphipod endemic to four spring systems in Comal County, Texas. It is a federally listed endangered species in the United States and classified as Endangered on the IUCN Red List due to its extremely limited geographic distribution. The species inhabits subterranean limestone aquifers and exhibits adaptations typical of stygobitic organisms, including light sensitivity and starvation resistance. Very few individuals have been documented since its listing, and no formal recovery plan or comprehensive population assessment exists as of 2022.
Stygobromus russelli
Russell's Cave Amphipod, Russell stygobromid
Stygobromus russelli is a subterranean amphipod species in the family Crangonyctidae, endemic to Texas in the United States. As a stygobiont, it inhabits groundwater systems in cave environments. The species was originally described by Holsinger in 1967 under the basionym Stygonectes russelli. Like other members of the genus Stygobromus, it exhibits troglomorphic adaptations including reduced pigmentation and eye development associated with life in permanent darkness.
Styloniscidae
Styloniscidae is a family of terrestrial isopods (woodlice) within the suborder Oniscidea. The family comprises at least twelve genera distributed across tropical and subtropical regions, with exceptional diversity documented in Brazilian karst systems. Multiple genera contain troglobitic (exclusively cave-dwelling) species, including Xangoniscus, Cylindroniscus, Pectenoniscus, and Chaimowiczia. These cave-dwelling representatives exhibit classic troglomorphic traits: anophthalmy (eye loss), depigmentation, and elongated appendages.
Symphytognathidae
dwarf orbweavers, micro orb-weavers
Symphytognathidae is a family of extremely small spiders (body size typically 1 mm or less, with Patu digua at 0.37 mm among the smallest known spiders). The family contains approximately 105 species in ten genera, including Crassignatha, Patu, Anapistula, and Micropholcomma. Members construct minute orb webs, often suspended between dead leaves in leaf litter or between vegetation. The family was historically placed in various superfamilies but molecular phylogenetics supports placement within Araneoidea, with affinities to Theridiosomatidae and Anapidae.
Taracidae
Taracid Harvestmen
Taracidae is a family of harvestmen (Opiliones) established by Schönhofer in 2013, containing four genera and 23 described species. The family includes the genera Taracus, Oskoron, Hesperonemastoma, and Crosbycus, though the placement of the latter two remains taxonomically disputed. Members are primarily distributed in western North America, with some species exhibiting troglomorphic adaptations suggesting cave-dwelling habits.
Taracus
Taracus is a genus of small harvestmen (Opiliones) in the family Taracidae. Most species inhabit limestone and lava caves in western North America, with body lengths ranging from 2.0 to 5.5 mm. The genus contains 14 described species as of 2023, predominantly distributed across the United States with limited representation in Russia.
Taracus marchingtoni
Taracus marchingtoni is a troglobiotic harvestman species endemic to lava caves in central Oregon. First collected in 1965 but not formally described until 2016, it exhibits classic cave-adapted traits including reduced eyes and depigmentation. The species is notable for its extremely elongated chelicerae, which in males can exceed body length. It has been documented feeding on troglophilic millipedes.
Tegenaria domestica
Barn Funnel Weaver, Domestic House Spider
Tegenaria domestica is a funnel-web spider in the family Agelenidae, native to Europe but now distributed nearly worldwide through human introduction. It is one of the smaller species in its genus, with females averaging 7.5–11.5 mm and males 6–9 mm in body length. The species is notable for building characteristic funnel-shaped webs and for recently documented colonial behavior in a unique cave environment in Greece/Albania, where thousands of individuals cooperatively maintained a communal web exceeding 100 square meters.
Teneriffiidae
Teneriffiidae is a family of prostigmatic mites in the order Trombidiformes, first described by Thor in 1911. These are moderate-sized, fast-walking predatory mites with a life cycle consisting of egg, prelarva, larva, protonymph, deutonymph, tritonymph, and adult stages. Taxonomic revision has reduced the number of valid genera to two: Teneriffia (palpgenu oncophysis absent) and Parateneriffia (palpgenu oncophysis present), with seven other genera synonymized. The family occupies diverse terrestrial habitats including trees, rocks, caves, and mountains, with some species adapted to subterranean environments.
Tetragnathidae
Long-jawed Orb Weavers, Long-jawed Orbweavers
Long-jawed orb weavers are a family of spiders characterized by elongated bodies, long legs, and often extraordinarily long chelicerae (jaws). Most species construct orb webs in a horizontal or near-horizontal plane, distinguishing them from the vertical webs typical of Araneidae. The family includes diverse ecological specialists: meadow-dwelling species that camouflage as grass stems, riparian species that build webs over water, and cave-dwelling species adapted to dimly lit environments. Some species exhibit social behavior, forming communal webs spanning extensive areas.
Texella
cave harvestmen, Texella harvesters
Texella is a genus of armored harvestmen (Opiliones: Phalangodidae) containing more than 20 described species. The genus is endemic to cave and karst systems of central Texas, where species exhibit varying degrees of troglomorphy. Several species, including T. reyesi and T. reddelli, are federally endangered due to extreme habitat restriction. Genetic studies reveal strong population structuring aligned with geologic karst fauna regions.
Tolus
Tolus is a monotypic genus of harvestmen in the family Phalangodidae, described by Goodnight & Goodnight in 1942. The sole described species, Tolus appalachius, is known only from two caves in Tennessee, United States. This genus represents a rare example of cave-adapted opilionid fauna in the Appalachian region.
Travunioidea
travunioid harvestmen, armoured harvestmen
Travunioidea is a superfamily of armoured harvestmen (Opiliones: Laniatores) comprising four families and approximately 75-77 described species. It represents an early-diverging lineage within the suborder Laniatores, characterized by a Laurasian distribution spanning eastern Asia, eastern and western North America, and south-central Europe. Recent phylogenomic studies using ultraconserved elements (UCEs) have revised the classification, establishing the families Travuniidae, Cladonychiidae, Paranonychidae, and Cryptomastridae, while rejecting traditional tarsal claw-based taxonomy due to widespread homoplasy.
Trichocera
winter crane flies
Trichocera is a genus of winter crane flies comprising over 140 described species. Adults are among the few insects regularly active during winter months, often appearing at porch lights or forming aerial swarms on sunny days. The genus is distinguished from other crane flies by the presence of three ocelli on the crown of the head. Most North American species belong to this genus, with larvae developing in decaying organic matter including leaf litter, compost, fungi, and manure.
Trichoniscidae
Trichoniscidae is a family of terrestrial isopods (woodlice) notable for containing the most abundant British woodlouse, *Trichoniscus pusillus*. The family exhibits exceptional ecological diversity, with many species occupying subterranean habitats in karst regions across Europe, while others have secondarily adapted to aquatic or amphibious lifestyles. Multiple genera contain troglobiotic (obligate cave-dwelling) species, particularly in the Dinaric Karst, which harbors significant diversity of this family. Some species demonstrate unique morphological adaptations for cave life, including elongated appendages and modified mouthparts.
Trichopetalidae
Trichopetalidae is a family of small millipedes in the order Chordeumatida. Adults possess 28 or 30 body segments, counting the collum as the first and the telson as the last. The family comprises seven genera and approximately 43 species, with members exhibiting diverse ecological strategies ranging from surface-dwelling to obligate cave-dwelling (troglobitic) lifestyles.
Trigoniophthalmus alternatus
Cave Bristletail
Trigoniophthalmus alternatus is a species of jumping bristletail, a primitive wingless insect in the order Archaeognatha. It is commonly known as the Cave Bristletail due to its association with subterranean and dark, moist habitats. The species has a broad distribution across Europe, Northern Asia (excluding China), and North America. It was originally described as Machilis alternatus by Silvestri in 1904 before being transferred to the genus Trigoniophthalmus.
Triphosa
Triphosa is a genus of moths in the family Geometridae, subfamily Larentiinae, established by Stephens in 1829. The genus occurs across the Holarctic region, with species documented in Europe, Asia, and North America. Several species, notably Triphosa dubitata and T. sabaudiata, exhibit obligate cave-dwelling behavior as adults, a distinctive ecological trait within the Geometridae. The genus has been subject to recent taxonomic revision in the Western Palaearctic, resulting in synonymies and description of new species.
Trogloraptor marchingtoni
cave robber spider
Trogloraptor marchingtoni is a large cave-dwelling spider and the sole species in the family Trogloraptoridae, the first new spider family described from North America since the 1890s. Discovered in 2010 in caves of southwestern Oregon, this species is distinguished by extraordinary hook-like claws on its legs used to capture prey. It represents a remarkable evolutionary lineage with no close known relatives among living spiders. The species name honors Neil Marchington, the deputy sheriff and amateur biologist who first brought the spiders to scientific attention.
Trogloraptoridae
Cave Robber Spiders
Trogloraptoridae is a family of spiders established in 2012 to accommodate the single genus Trogloraptor, found in caves and old-growth forests of the Pacific Northwest. The family was erected based on the unique morphology of Trogloraptor marchingtoni, which possesses distinctive raptorial claws unlike any other known spider. This discovery marked the first new family of spiders described from North America since the 1890s. The family represents a significant evolutionary lineage that has forced revisions to understanding of spider phylogeny.
Tularina
Tularina is a genus of harvestmen (Opiliones: Laniatores) in the family Phalangodidae, described by Ubick & Briggs in 2008. As a member of the infraorder Grassatores, it belongs to a diverse group of long-legged arachnids commonly known as daddy longlegs. The genus was established based on morphological characteristics distinguishing it from related phalangodid genera. Information regarding species diversity, distribution, and biology remains limited in published literature.
Typhlobius
Typhlobius is a genus of lithobiid centipedes established by Chamberlin in 1922. These centipedes belong to the order Lithobiomorpha, characterized by having 15 pairs of legs in adults. The genus is distinguished by adaptations to subterranean environments, including reduced or absent eyes. Species within this genus are poorly known, with limited published ecological or biological data available.
Typhlobius kebus
Typhlobius kebus is a lithobiomorph centipede described by Chamberlin in 1922. It belongs to the genus Typhlobius, a group of lithobiid centipedes. The species has been documented from California, USA. Very little is known about its biology or ecology.
Zuphiini
Zuphiini is a tribe of ground beetles in the family Carabidae, established by Bonelli in 1810. The tribe contains at least 23 genera and more than 120 described species with a worldwide distribution. Members of the genus Coarazuphium within this tribe include obligate cave-dwelling (troglobitic) species found in iron ore caves in Brazil's Carajás region, which harbors the highest diversity of obligatory cave-dwelling beetles in the country.