Plectreuridae, also called plectreurid spiders, is a small spider family confined to the Southwestern United States,

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, and the Caribbean. Only two living genera are known—the nominate genus '' Plectreurys'' and '' Kibramoa''. In the past, the family was more widespread, with the

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

genus '' Eoplectreurys'' known from China, the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

'' Palaeoplectreurys baltica'' from

Baltic amber The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite. It was produced sometime during the Eocene epoch, but exactly when is controversial. It has been estimated that these forests created more than ...

and the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

'' Plectreurys pittfieldi'' from Dominican amber. These

ecribellate 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 ...

, haplogyne spiders build haphazard webs under rocks and dead cacti. Adult males can be found wandering at night. Relatively little is known of their biology. Unlike the sicariids, scytodids, and diguetids, to which they are most closely related, they have eight eyes. In appearance females of ''Plectreurys'' resemble those of the larger species of the cribellate Filistatidae. They differ in their eye arrangement and in having the

femurs The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with t ...

on the first pair of legs bowed.

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: *'' Kibramoa'' Chamberlin, 1924 — United States, Mexico *'' Plectreurys'' Simon, 1893 — North America, Cuba, Central America *†'' Eoplectreurys'' Selden & Huang, 2010 * †'' Palaeoplectreurys'' Wunderlich, 2004

References

External links

{{Taxonbar, from=Q11683 Araneomorphae families Extant Middle Jurassic first appearances