Araneomorphae
Guides
Cheiracanthiidae
Long-legged Sac Spiders
Cheiracanthiidae is a family of araneomorph spiders established by Wagner in 1887, with priority over the synonym Eutichuridae. The family contains approximately 15 genera and 385 species as of 2026, with Cheiracanthium being the largest and most species-rich genus. Members are commonly known as long-legged sac spiders. The family's phylogenetic placement has been historically contested, having been assigned to Clubionidae, Miturgidae, and Eutichuridae before recognition as a distinct family. Molecular analyses indicate Cheiracanthium is paraphyletic, with divergence estimated at 67 million years ago.
Corinnidae
corinnid sac spiders, ground and ant-mimic sac spiders
Corinnidae is a family of araneomorph spiders comprising over 800 species in 71+ genera worldwide. Formerly part of the catch-all family Clubionidae, the group was redefined in 2014 to include only subfamilies Corinninae and Castianeirinae. Members are wandering predators that construct silken sac retreats, with many genera exhibiting ant-mimicry as a defensive strategy. The family includes notable ant-mimicking genera such as Castianeira, Myrmecotypus, Mazax, and Myrmecium.
Enoplognatha intrepida
Enoplognatha intrepida is a cobweb spider in the family Theridiidae, characterized by its membership in the infraorder Araneomorphae. The species has a notably disjunct distribution spanning North America (USA, Canada, Greenland) and East Asia (Korea). It is one of several species in the genus Enoplognatha, which includes the well-studied and polymorphic E. ovata.
Gertschanapis
Gertschanapis is a genus of minute araneomorph spiders in the family Anapidae. The genus contains a single species, Gertschanapis shantzi, described by Norman I. Platnick and Raymond Robert Forster in 1990. It is known only from the United States.
Kibramoa madrona
Kibramoa madrona is a true spider in the family Plectreuridae, described by Gertsch in 1958. It is found in the United States. Members of this family are typically found in arid and semi-arid regions of western North America.
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.
Litopyllus temporarius
Litopyllus temporarius is a ground spider species in the family Gnaphosidae, described by Chamberlin in 1922. It belongs to the infraorder Araneomorphae, the group containing most modern spider species. The species is known only from the United States, though specific habitat details and ecological information remain undocumented.
Meriola
Meriola is a genus of araneomorph spiders in the family Trachelidae, established by Nathan Banks in 1895. The genus contains approximately 24 species distributed primarily in South America, with some species extending into North America. Several species have been introduced to the United States, notably Meriola arcifera in California and Hawaii. The genus is taxonomically distinct from a homonymous genus of crabs in the family Xanthidae.
Mimetidae
Pirate spiders
Pirate spiders (Mimetidae) are a family of araneomorph spiders renowned for their specialized araneophagic behavior—they hunt and feed on other spiders rather than building webs to capture prey. Members of this family employ aggressive mimicry, infiltrating the webs of cobweb weavers, orb weavers, and other spiders, then subduing their hosts with spider-specific venom. The family contains approximately 200 species across 12 genera worldwide, with highest diversity in the Neotropics. North America hosts 18 described species in three genera, with another ten species awaiting formal description. These small spiders (typically 3–7 mm body length) are characterized by long leg spines and distinctive eye arrangements.
Miturgidae
Prowling Spiders
Miturgidae is a family of araneomorph spiders commonly known as prowling spiders. The family includes approximately 160-200 species across 33 genera worldwide. Members are small to medium-sized, active hunters that do not construct permanent webs for prey capture. The family has undergone substantial taxonomic revision, with the former family Zoridae synonymized and the genus Cheiracanthium (longlegged sac spiders) transferred to the separate family Cheiracanthiidae.
Opopaea
goblin spiders
Opopaea is a large genus of minute goblin spiders in the family Oonopidae, containing approximately 180-190 accepted species. These spiders are characterized by their extremely small size (under 2 mm), six-eyed arrangement, and reddish-brown coloration. The genus is one of the most species-rich within the Oonopidae family, with representatives found across multiple continents including Australia and Sri Lanka. Species in this genus inhabit leaf litter and forest floor habitats, where their diminutive size and cryptic coloration make them difficult to detect.
Philodromus anomalus
running crab spider
Philodromus anomalus is a running crab spider in the family Philodromidae, first described by Gertsch in 1934. It is a member of the infraorder Araneomorphae, the "true spiders." The species is known from the United States, though specific details about its biology and ecology remain limited in published literature.
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.
Physocyclus
cellar spiders
Physocyclus is a genus of cellar spiders (family Pholcidae) established by Eugène Louis Simon in 1893. The genus comprises 38 recognized species distributed across multiple continents, with the highest diversity in Mexico. Two distinct species groups are recognized: the globosus group (11 species) and the dugesi group (21 species), distinguished by morphological and biogeographic patterns. The type species, P. globosus, has been widely introduced globally through human activity.
Physocyclus californicus
A cellar spider species in the family Pholcidae, distributed across the southwestern United States and Mexico. Adults are active during fall months, with males wandering in search of mates. The species frequently occurs in human dwellings, where it constructs webs in ceiling corners and other sheltered locations.
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.
Socalchemmis idyllwild
Socalchemmis idyllwild is a spider species in the family Zoropsidae, first described by Platnick and Ubick in 2001. The genus Socalchemmis is endemic to southern California and represents a group of spiders previously placed in Tengellidae. The species name references Idyllwild, California, indicating the type locality. This species belongs to a genus characterized by distinctive morphological features separating it from related zoropsid genera.
Sosticus insularis
Long Island Crevice Ground Spider
Sosticus insularis is a ground spider in the family Gnaphosidae, characterized by its association with rocky crevice habitats. The species was originally described as Prosthesima insularis by Banks in 1895 and later transferred to Sosticus. It occurs in northeastern North America, with records from the United States and Canada. The common name 'Long Island Crevice Ground Spider' reflects both its geographic association and habitat preference. As a member of the Gnaphosidae, it is a wandering hunter rather than a web-builder.
Theridiidae
tangle-web spiders, cobweb spiders, comb-footed spiders
Theridiidae is a large, globally distributed family of araneomorph spiders comprising over 2,600 species in more than 130 genera. Members are characterized by a comb of serrated bristles (setae) on the tarsus of the fourth leg, used to manipulate silk. The family exhibits remarkable diversity in web architecture, ranging from irregular tangle webs to specialized gumfoot webs and sheet-like structures. Theridiids are ecribellate, producing sticky capture silk rather than woolly silk, and are entelegyne with females possessing a genital plate. The family includes medically significant species such as widow spiders (Latrodectus), model organisms for social behavior research (Anelosimus), and specialized kleptoparasites (Argyrodinae).
Trochosa abdita
Trochosa abdita is a wolf spider (family Lycosidae) described by Gertsch in 1934. It belongs to the genus Trochosa, a group of ground-dwelling hunting spiders characterized by their distinctive eye arrangement. The species is known only from the United States, though specific details about its ecology and behavior remain poorly documented in the scientific literature.