Cave-dwelling
Guides
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.