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Dysderoidea
The Dysderoidea are a clade or superfamily of araneomorph spiders. The monophyly of the group, initially consisting of the four families Dysderidae, Oonopidae, Orsolobidae and Segestriidae, has consistently been recovered in phylogenetic studies. In 2014, a new family, Trogloraptoridae, was created for a recently discovered species ''Trogloraptor marchingtoni''. It was suggested that Trogloraptoridae may be the most basal member of the Dysderoidea clade. However, a later study found that Trogloraptoridae was placed outside the Dysderoidea and concluded that it was not part of this clade. Phylogeny Dysderoidea are members of the Haplogynae clade: spiders with simpler copulatory organs (palpal bulbs and epigynes) than other araneomorphs. One hypothesis for relationships within the Haplogynae is shown below. The status of the Trogloraptoridae is unclear. The family was not included in one study which otherwise found the same topography, but it was placed outside even the Filista ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orsolobidae
Orsolobidae is a six-eyed spider family with about 180 described species in thirty genera. It was first described by J. A. L. Cooke in 1965, and was raised to family status from "Dysderidae" in 1985. Genera Most genera are endemic to New Zealand and the Australian region, but several genera occur in southern Africa and South America. , the World Spider Catalog accepts the following genera: *'' Afrilobus'' Griswold & Platnick, 1987 — South Africa, Malawi *'' Anopsolobus'' Forster & Platnick, 1985 — New Zealand *'' Ascuta'' Forster, 1956 — New Zealand *'' Australobus'' Forster & Platnick, 1985 — Australia *'' Azanialobus'' Griswold & Platnick, 1987 — South Africa *'' Basibulbus'' Ott, Platnick, Berniker & Bonaldo, 2013 *'' Bealeyia'' Forster & Platnick, 1985 — New Zealand *''Calculus'' Purcell, 1910 — South Africa *'' Chileolobus'' Forster & Platnick, 1985 — Chile *'' Cornifalx'' Hickman, 1979 — Australia *'' Dugdalea'' Forster & Platnick, 1985 — New Zealand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trogloraptoridae
''Trogloraptor'' is a genus of large spiders found in the caves of southwestern Oregon. It is the sole genus in the family Trogloraptoridae, and includes only one species, ''Trogloraptor marchingtoni''. These spiders are predominantly yellow-brown in color with a maximum leg span of . They are remarkable for having hook-like claws on the raptorial last segments of their legs. ''Trogloraptor'' belongs to one of only three new spider families described since 1990. The specific name is in honor of the amateur cave biologist and deputy sheriff Neil Marchington. Discovery The spiders were first collected in 2010 by Geo Graening, Neil Marchington, Ron Davis and Daniel Snyder, cave conservationists from the Western Cave Conservancy. They were described in 2012 by a research team consisting of arachnologists Charles Griswold, Tracy Audisio and Joel Ledford of the California Academy of Sciences. The male holotype was recovered from the M2 cave near Grants Pass, Oregon, on July 29, 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caponiidae
Caponiidae is a family of ecribellate haplogyne spiders that are unusual in a number of ways. They differ from other spiders in lacking book lungs and having the posterior median spinnerets anteriorly displaced to form a transverse row with the anterior lateral spinnerets. Most species have only two eyes, which is also unusual among spiders. A few species of Caponiidae variously have four, six or eight eyes. In some species the number of eyes will increase when the spiderling changes its skin as it grows towards adulthood. Description These spiders of about are rarely noticed, but generally look like somewhat faded woodlouse hunter spiders in the genus ''Dysdera''. The carapace (cephalothorax or prosoma) is orange and the abdomen (opisthosoma) light gray. The two-eyed species have their two eyes in the anterior middle of the carapace. Eye numbers Caponiidae are unusual in the degree to which the eye number varies. In this they surpass even the family Cybaeidae in which some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segestriidae
Tube-dwelling spiders (Segestriidae) are a family of araneomorph spiders first described by Eugène Simon in 1893. It consists of five genera, two large and widespread, '' Segestria'' and ''Ariadna'', and three smaller genera, '' Citharoceps'', '' Gippsicola'' and '' Indoseges''. They are haplogyne spiders, related to the Dysderidae and placed in clade or superfamily Dysderoidea. Members of this family are easily recognized because their first three pairs of legs are arranged forward instead of two and they have six eyes instead of eight, arranged in a semicircle. The leg structure appears to be an adaptation for living in silken tubes. Unlike those of the atypical tarantulas, these tubes may branch and are often built in tree bark fissures, as well as under stones. Both ''Segestria'' and ''Ariadna'' live in North America, South America, Eurasia, Africa and New Zealand, though ''Ariadna'' also lives in Australia. Genera , the World Spider Catalog accepts the following gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segestria Florentina
''Segestria florentina'' is the biggest European segestriid spider. Some vernacular names are green-fanged tube web spider and cellar spider, although the latter is not exclusive to this species. Description Females can reach a body length of 22 mm, males up to 15 mm. This species is much darker than others of the same genus. While subadult spiders have a greyish opisthosoma with a marking similar to '' Segestria senoculata'', adults are of a uniform black, sometimes with a green iridescent shine, especially on the chelicerae,Bellmann, H. (1997). Kosmos-Atlas Spinnentiere Europas. ''Kosmos''. which reflect with a striking green. The sexes are similar. Adults occur from June to November. Habits They spin a tubular web, often in cracks of buildings. Six or more silken lines radiate from it, and the spider waits in the entrance, touching the lines with the frontal six legs. Prey triggering these lines get caught, and the spider immediately retreats again to eat it. Howev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 recent molecular phylogenetic studies refute this, although many of the ecribellate haplogynes do appear to form a clade, Synspermiata. Unlike the Entelegynae, haplogynes lack hardened (sclerotized) female genitalia (epigynes). Most of the species within this group have six eyes, as opposed to most other spiders. Spiders in the genus '' Tetrablemma'' (Tetrablemmidae) have only four eyes, as do some members of the family Caponiidae; caponiids may even have only two eyes. However, spiders in the family Plectreuridae have the normal eight eyes. Phylogeny The Haplogynae are one of the two major groups into which araneomorph spiders were traditionally divided, the other being the Entelegynae. In 2005, Coddington summarized the relationships of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrablemmidae
Tetrablemmidae, sometimes called armored spiders, is a family of tropical araneomorph spiders first described by Octavius Pickard-Cambridge in 1873. It contains 126 described species in 29 genera from southeast Asia, with a few that occur in Africa and Central and South America. Pacullidae was incorporated into this family in 1981, but was later restored as a separate family in a 2016 phylogenetic study. Most species have been collected from litter and soil, including that of epiphytes. Some live in caves and show typical adaptations of cave spiders, such as loss of eyes and weak sclerotization. Members of '' Tetrablemma'' only have four eyes, a trait in spiders only found in these and certain members of Caponiidae. Genera , the World Spider Catalog accepts the following genera: *'' Ablemma'' Roewer, 1963 — Papua New Guinea, Asia *'' Afroblemma'' Lehtinen, 1981 — Angola, Tanzania, Congo *'' Anansia'' Lehtinen, 1981 — Angola *'' Bacillemma'' Deeleman-Reinhold, 1993 — Tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 species worldwide. One of the most abundant members of this family in the Americas is the southern house spider (''Kukulcania hibernalis''). Named after the fierce Meso-American god Kukulkan, 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 that are held together in front of their carapaces like the horn of a unicorn. The males also have a darker streak on the center of the dorsal carapace that causes them to be often mistaken for brown recluse spiders. 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 boo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribosomal DNA
Ribosomal DNA (rDNA) is a DNA sequence that codes for ribosomal RNA. These sequences regulate transcription initiation and amplification, and contain both transcribed and non-transcribed spacer segments. In the human genome there are 5 chromosomes with nucleolus organizer regions: the acrocentric chromosomes 13 (RNR1), 14 ( RNR2), 15 ( RNR3), 21 (RNR4) and 22 (RNR5). The genes that are responsible for encoding the various sub-units of rRNA are located across multiple chromosomes in humans. But the genes that encode for rRNA are highly conserved across the domains, with only the copy numbers involved for the genes having varying numbers per species. In Bacteria, Archaea, and chloroplasts the rRNA is composed of different (smaller) units, the large (23S) ribosomal RNA, 16S ribosomal RNA and 5S rRNA. The 16S rRNA is widely used for phylogenetic studies. Eukaryotes The rRNA transcribed from the approximately 600 rDNA repeats forms the most abundant section of RNA found in cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigyne
The epigyne or epigynum is the external genital structure of female spiders. As the epigyne varies greatly in form in different species, even in closely related ones, it often provides the most distinctive characteristic for recognizing species. It consists of a small, hardened portion of the exoskeleton located on the underside of the abdomen, in front of the epigastric furrow and between the epigastric plates. Functions The primary function of the epigyne is to receive and direct the palpal organ of the male during copulation. The various specific forms of epigynes are correlated, in each case, with corresponding specific differences in the palpus of the male. This specialization prevents individuals of different species from mating. The epigyne covers or accompanies the openings of the spermathecae, which are pouches for receiving and retaining sperm. Frequently, the openings of the spermathecae are on the outer face of the epigyne and can be easily seen. A secondary functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palpal Bulb
The two palpal bulbs – also known as palpal organs and genital bulbs – are the copulatory organs of a male spider. They are borne on the last segment of the pedipalps (the front "limbs" of a spider), giving the spider an appearance often described as like wearing boxing gloves. The palpal bulb does not actually produce sperm, being used only to transfer it to the female. Palpal bulbs are only fully developed in adult male spiders and are not completely visible until after the final moult. In the majority of species of spider, the bulbs have complex shapes and are important in identification. Structure The palpal bulb of a mature male spider is borne on the last segment of the pedipalp. This segment usually has touch-sensitive hairs (setae) with nerves leading to them. The bulb itself is entirely without nerves, and hence without sensory organs and muscles, since these depend on nerves for their functioning, although some spiders have one or two muscles external to the bulb and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyly
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic groups are typically characterised by shared derived characteristics ( synapomorphies), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly. The word "mono-phyly" means "one-tribe" in Greek. Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A ''paraphyletic group'' consists of all of the descendants of a common ancestor minus one or more monophyletic groups. A '' polyphyletic group'' is characterized by convergent features or habits of scientific interest (for example, night-active primates, fruit trees, aquatic insects). The features by which a polyphyletic group is differentiated from others are not inherited from a common ancestor. These definitions have taken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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