Crevice weaver spiders (Filistatidae) comprise

cribellate Cribellum literally means "little sieve", and in biology the term generally applies to anatomical structures in the form of tiny perforated plates. In certain groups of diatoms it refers to microscopically punctured regions of the frustule, or o ...

spiders with features that have been regarded as " primitive" for

araneomorph The Araneomorphae (also called the Labidognatha) are an infraorder of spiders. They are distinguishable by chelicerae (fangs) that point diagonally forward and cross in a pinching action, in contrast to the Mygalomorphae (tarantulas and their cl ...

spiders. They are weavers of funnel or tube webs. The family contains 18 genera and more than 120 described species worldwide. One of the most abundant members of this family in the

Americas The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. Along with th ...

is the

southern house spider The southern house spider is a species of large spider in the family Filistatidae. Currently given the scientific name ''Kukulcania hibernalis'', it was formerly known as ''Filistata hibernalis''. Found in the Americas, it exhibits strong sexual ...

(''Kukulcania hibernalis''). Named after the fierce Meso-American god

Kukulkan K’uk’ulkan, also spelled Kukulkan, ( "''Plumed Serpent''", "''Amazing Serpent''") is the name of a Mesoamerican serpent deity that was worshipped by the Yucatec Maya people of the Yucatán Peninsula before the Spanish conquest of Yucat ...

, the females are large (up to nearly 20 mm) dark-colored spiders and males are light brown, smaller (about 10 mm), but more long-legged and with

palps Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicerae ("jaws") a ...

that are held together in front of their

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

s like the horn of a

unicorn The unicorn is a legendary creature that has been described since antiquity as a beast with a single large, pointed, spiraling horn projecting from its forehead. In European literature and art, the unicorn has for the last thousand years o ...

. The males also have a darker streak on the center of the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

carapace that causes them to be often mistaken for

brown recluse spider The brown recluse (''Loxosceles reclusa''), Sicariidae (formerly placed in a family "Loxoscelidae") is a recluse spider with necrotic venom. Similar to those of other recluse spiders, their bites sometimes require medical attention. The brown r ...

s. The tiny members of the genus ''Filistatinella'' are like miniature versions of ''Kukulcania''. The nominate genus ''Filistata'' is Afro-Eurasian in distribution. In many older books the species from the Americas now placed in the genus ''Kukulcania'' are placed in ''Filistata''. A striking visual characteristic of the family, beside dimorphism, is the unusual upward bend encountered near the femur of the first pair of legs. While resembling hydraulic muscle mechanisms akin to arthropods, this modification actually allows the spider to retain the prey directly from the crevice it occupies. Also, if the larger prey ever tries to pull it from the crevice, the spider can use these legs to "grab" to the side walls and hence make it difficult. Many ''Kukulcania'' species also use them to dig holes in the soft ground at a 25- to 30-degree angle.

Taxonomy

The family Filistatidae was created in 1867 by Anton Ausserer. It was based on the species he called ''Filistata bicolor'' (now '' Filistata insidiatrix''), a Mediterranean species also found in southern Austria.

Phylogeny

On the basis of the features of the male and female genitalia, the family was placed in the

Haplogynae The Haplogynae or haplogynes are one of the two main groups into which araneomorph spiders have traditionally been divided, the other being the Entelegynae. Morphological phylogenetic studies suggested that the Haplogynae formed a clade; more recen ...

, usually as the sister taxon of the remaining members of the group. However, unlike the other haplogynes, Filistatidae are

and do not show a decrease in the number of segments of the anterior lateral spinnerets. They have other features which have been regarded as "primitive": an M-shaped intestine, only leg IV moving while combing silk, and posterior book lung leaves being present in early juveniles. A 2013 study based on molecular evidence placed the family as sister to a clade consisting of

Hypochilidae Lampshade spiders, family Hypochilidae, are among the most primitive of araneomorph spiders. There are two genera and twelve species currently recognized. Like mygalomorphs, most hypochilids have two pairs of book lungs, but like araneomorphs th ...

and the remaining haplogynes. The precise phylogenetic position of the family was described in 2014 as "one of the most enigmatic problems in spider phylogeny". A 2015 study, based on genomic data, places Filistatidae with Hypochilidae in a clade outside most of the families previously placed in Haplogynae: This placement suggests that features that were thought to be "primitive" to araneomorph spiders as a whole (such as an M-shaped midgut) could actually be novel derived features ( synapomorphies) of the Hypochilidae-Filistatidae clade.

Genera

, the

World Spider Catalog The World Spider Catalog (WSC) is an online searchable database concerned with spider taxonomy. It aims to list all accepted families, genera and species, as well as provide access to the related taxonomic literature. The WSC began as a series of ...

accepts the following genera: *'' Afrofilistata'' Benoit, 1968 — Sudan *'' Andoharano'' Lehtinen, 1967 — Namibia, Madagascar *'' Antilloides'' Brescovit, Sánchez-Ruiz & Alayón, 2016 — Mexico *'' Filistata'' Latreille, 1810 — Australia, Asia *'' Filistatinella'' Gertsch & Ivie, 1936 — Mexico, United States *'' Filistatoides'' F. O. Pickard-Cambridge, 1899 — Guatemala, Chile, Cuba *''

Kukulcania ''Kukulcania'' is a genus of crevice weavers that was first described by Pekka T. Lehtinen in 1967. It is named after Kukulkan, a Mesoamerican serpent deity. Species it contains fifteen species found in the Americas, including the United Stat ...

'' Lehtinen, 1967 — North America, Central America, Chile *'' Labahitha'' Zonstein, Marusik & Magalhaes, 2017 — Malaysia *'' Lihuelistata'' Ramírez & Grismado, 1997 — Argentina *'' Microfilistata'' Zonstein, 1990 — Iran, Turkmenistan, Tajikistan *'' Misionella'' Ramírez & Grismado, 1997 — Brazil, Argentina *'' Pholcoides'' Roewer, 1960 — Afghanistan, Tajikistan, India *'' Pikelinia'' Mello-Leitão, 1946 — South America *'' Pritha'' Lehtinen, 1967 — Asia, Oceania, Africa, France *'' Sahastata'' Benoit, 1968 — Asia, Eritrea *'' Tricalamus'' Wang, 1987 — China, Japan, Afghanistan *'' Wandella'' Gray, 1994 — Australia *'' Yardiella'' Gray, 1994 — Australia *'' Zaitunia'' Lehtinen, 1967 — Asia, Greece Kukulcaniahibernalis.JPG, ''Kukulcania hibernalis'' male

References

{{Taxonbar, from=Q10534 Spiders of South America

Taxonomy

Phylogeny

Genera

See also

References