The mygalomorph spider family Nemesiidae includes 364 described species (Platnick 2013). The family has a worldwide distribution, but only five (at most) valid species occur in North America north of Mexico, all belonging in the genus Calisoga (Ubick and Ledford 2005). Of these North American species, according to Ubick and Ledford, Brachythele longitarsis and B. anomala clearly belong in the genus Calisoga but were never formally transferred to this genus. For this reason, Platnick still lists them in Brachythele and lists only three Calisoga species (C. centronetha, C. sacra, and C. theveneti—and Ubick and Ledford report that according to M.M. Bentzien in his unpublished 1976 Ph.D. thesis, "C. theveneti" are actually just very small C. longitarsis).
Nemesiids resemble tarantulas (Theraphosidae), although they are generally smaller and more slightly built; close inspection reveals that they lack the conspicuous claw tufts at the tips of their legs that are evident in theraphosids and the tips of their tarsi bear three claws instead of the two present in theraphosids.
Calisoga is known from northern and central California, with a single record from western Nevada. These spiders are found in a range of habitats, mainly oak grasslands, riparian areas, and coniferous forests, from near sea level to around 2300 m elevation, sometimes occurring even in urban areas. Calisoga live in burrows or in crevices in the ground which they line with silk and hide in as they wait for passing prey. Mature males leave their burrows to search for females and females are often flooded out of their burrows in the rainy season. Females place their egg sacs in their burrows. Calisoga sometimes enter human homes, where their large and hairy appearance, conspicuous threat display, and aggressive behavior can cause alarm, although they are not dangerous to humans. (Ubick and Ledford 2005; Bradley 2013)
In Australia, nemesiids are known as wishbone spiders because they often build forked burrows with two openings at the soil surface that would resemble a wishbone if viewed in cross section (Main 1976 cited in Bradley 2013).
Ubick and Ledford (2005) reviewed the taxonomic history of the small number of Nearctic nemesiids.
Nemesiidae, also known as funnel-web trapdoor spiders, is a family of mygalomorph[1] spiders first described by Eugène Simon in 1889,[2] and raised to family status in 1985. Before becoming its own family, it was considered part of "Dipluridae".[3]
Nemesiidae are relatively large spiders with robust legs and a body that is nearly three times as long as it is wide. They are darkly colored, brown to black, though some have silvery hairs on their carapace.[4] Atmetochilus females can grow over 4 centimetres (1.6 in) long.
They live in burrows, often with a hinged trapdoor. This door is pushed up while the spider waits for passing prey. They rarely leave their burrows, catching prey and withdrawing as quickly as possible. Some of these burrows have a side tubes, but it is not certain whether Sinopesa builds burrows at all.[5]
As of July 2020, the World Spider Catalog accepts the following genera:[6]
Transferred to other families:[7][8][9][10][11]
†Eodiplurina Petrunkevitch 1922 Florissant Formation, United States, Eocene
Nemesiidae, also known as funnel-web trapdoor spiders, is a family of mygalomorph spiders first described by Eugène Simon in 1889, and raised to family status in 1985. Before becoming its own family, it was considered part of "Dipluridae".
