Plectreuridae, also called plectreurid spiders, is a small
spider family confined to the
Southwestern United States
The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Ne ...
,
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
The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Se ...
.
Only two living
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
are known—the nominate genus ''
Plectreurys'' and ''
Kibramoa''. In the past, the family was more widespread, with the
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), 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 J ...
genus ''
Eoplectreurys'' known from
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, the
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...
''
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 1 ...
and the
Miocene
The Miocene ( ) is the first 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 means "less recen ...
''
Plectreurys pittfieldi'' from
Dominican amber
Dominican amber is amber from the Dominican Republic derived from resin of the extinct tree ''Hymenaea protera''.
Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has a higher number of fossil incl ...
.
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
web
Web most often refers to:
* Spider web, a silken structure created by the animal
* World Wide Web or the Web, an Internet-based hypertext system
Web, WEB, or the Web may also refer to:
Computing
* WEB, a literate programming system created by ...
s under rocks and dead
cacti
A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...
. 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
Crevice weaver spiders (Filistatidae) comprise cribellate spiders with features that have been regarded as " primitive" for araneomorph spiders. They are weavers of funnel or tube webs. The family contains 18 genera and more than 120 described sp ...
. 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