Troglomorphic
Guides
Anillinus jancae
Anillinus jancae is a small, eyeless ground beetle in the tribe Bembidiini. It was described by Thomas C. Barr in 1995 based on specimens from Kentucky. The species belongs to a genus of minute carabids adapted to subterranean or deep soil habitats. Like other Anillinus species, it exhibits troglomorphic traits including reduced pigmentation and vestigial eyes.
Brackenridgia
woodlice
Brackenridgia is a genus of small terrestrial isopods (woodlice) in the family Trichoniscidae, established by Ulrich in 1902. The genus contains nine described species distributed primarily in North America, with several species exhibiting troglomorphic adaptations for cave-dwelling. Species in this genus are typically found in moist, dark microhabitats including caves, forest litter, and rocky crevices.
Catopocerus appalachianus
Catopocerus appalachianus is a small beetle species in the family Leiodidae, subfamily Catopocerinae. It was described by Peck in 1975 and is endemic to the Appalachian region of the eastern United States. The species belongs to a genus characterized by reduced eyes and subterranean or cave-associated habits. Records indicate it has been collected from Alabama, Illinois, Kentucky, North Carolina, Tennessee, Virginia, and West Virginia.
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.
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.
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.
Horologion
Horologion is one of the rarest and most enigmatic carabid beetle genera, containing two known species of troglomorphic ground beetles endemic to the middle Appalachian Mountains. The genus remained monotypic for over 60 years after its description in 1932, with a second species discovered in Virginia in 1991 and described in 2024. Phylogenetic analysis places Horologion in supertribe Trechitae as sister to the Gondwanan tribe Bembidarenini, making tribe Horologionini a relict lineage with no close relatives in the Northern Hemisphere.
Nesticus carolinensis
Linville Caverns Spider
Nesticus carolinensis is a species of cave-dwelling spider in the family Nesticidae, first described by Bishop in 1950 under the basionym Ivesia carolinensis. The species is endemic to the southeastern United States and is commonly known as the Linville Caverns Spider. Like other members of the genus Nesticus, it exhibits adaptations to subterranean habitats including reduced pigmentation and elongated appendages.
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.
Pseudanophthalmus tenuis
Blue River cave beetle
Pseudanophthalmus tenuis is a small, eyeless ground beetle endemic to karst cave systems in Indiana, United States. Formerly considered to contain multiple subspecies, these have been elevated to full species status under Pseudanophthalmus stricticollis. The species is part of a genus specialized for subterranean life, with reduced visual structures and elongated appendages adapted to darkness.
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.
Sensillanura caeca
Sensillanura caeca is a species of springtail in the family Neanuridae, first described by Folsom in 1916. The species epithet "caeca" (Latin for "blind") suggests an adaptation to subterranean or cave-dwelling habitats, a trait common among troglobitic springtails. As a member of the order Poduromorpha, it belongs to one of the most diverse groups of Collembola. Very few specific details about its biology have been documented in accessible literature.
Sitalcina
Sitalcina is a genus of armoured harvestmen (Opiliones) in the family Phalangodidae, established by Nathan Banks in 1911. The genus contains approximately 10 described species, all endemic to western North America, primarily distributed in California and adjacent regions. These harvestmen belong to the suborder Laniatores, a group characterized by relatively short legs and heavily sclerotized body armor. Most species have been described from cave or deep-soil habitats, reflecting a troglomorphic or endogean lifestyle.
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.
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.
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.
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.
Troglomethes leechi
false soldier beetle
Troglomethes leechi is a species of false soldier beetle in the family Omethidae. The species was described by Wittmer in 1970 and is known from North America. Members of the genus Troglomethes are associated with subterranean or cave-like habitats.
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.
Typhlusechus singularis
Typhlusechus singularis is a species of darkling beetle (Tenebrionidae) described by Linell in 1897. The genus Typhlusechus contains few described species and is characterized by reduced or absent eyes, an adaptation associated with subterranean or cave-dwelling habits. This species is part of a group of tenebrionids that have evolved morphological specializations for life in darkness, including elongated appendages and depigmentation. Records indicate extremely limited observation data, with only 4 documented observations in iNaturalist.