|
Austrochiloidea
The Austrochiloidea or austrochiloids are a group of araneomorph spiders, treated as a superfamily. The taxon contains two families of eight-eyed spiders: * Austrochilidae Zapfe, 1955 * Gradungulidae Forster, 1955 Phylogeny The monophyly of the Austrochiloidea has been supported in both morphological and molecular phylogenetic studies. The position of the clade relative to two much larger groups, Haplogynae and Entelegynae The Entelegynae or entelegynes are a subgroup of araneomorph spiders, the largest of the two main groups into which the araneomorphs were traditionally divided. Females have a genital plate ( epigynum) and a "flow through" fertilization system; m ..., has varied. A summary in 2005 showed the Austrochiloidea to be basal to both groups: Two studies have placed representatives of the Austrochiloidea between the two, suggesting they have more derived characters than previously supposed: References {{Taxonbar, from=Q54482 Araneomorphae Arachnid super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araneomorphae
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 close kin), where they point straight down. Araneomorphs comprise the vast majority of living spiders. Distinguishing characteristics Most spider species are Araneomorphae, which have fangs that face towards each other, increasing the orientations they can employ during prey capture. They have fewer book lungs (when present), and the females typically live one year. The Mygalomorphae have fangs that face towards the ground, and which are parallel to the long axis of the spider's body, thus they have only one orientation they can employ during prey capture. They have four pairs of book lungs, and the females often live many years. Image:Atrax robustus.jpg, This ''Atrax robustus'' shows the orientation of Myglamorphae fangs. Image:Che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gradungula Sorenseni
''Gradungula'' is a monotypic genus of South Pacific large-clawed spiders containing the single species, ''Gradungula sorenseni''. It is only found in New Zealand. __TOC__ Etymology The genus name is derived from Latin ' "step" and ' "claw", referring to the enlarged front leg claws of this species. These claws also occur in other species of the family Gradungulidae. The species name "''sorenseni''" is named after Jack Sorensen, the discoverer of the species. Taxonomy ''Gradungula sorenseni'' was first described by Raymond Robert Forster in 1955. Distribution ''Gradungula sorenseni'' is distributed in forests throughout the western South Island and throughout Stewart Island Stewart Island ( mi, Rakiura, ' glowing skies', officially Stewart Island / Rakiura) is New Zealand's third-largest island, located south of the South Island, across the Foveaux Strait. It is a roughly triangular island with a total land ar .... Forster, R. R., Platnick, N. I. & Gray, M. R. ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austrochilidae
Austrochilidae is a small spider family with nine species in two genera. ''Austrochilus'' and ''Thaida'' are endemic to the Andean forest of central and southern Chile and adjacent Argentina. Taxonomy , two genera are placed in the family Austrochilidae: ''Austrochilus'' and ''Thaida'', found in Chile and Argentina. The taxonomic placement of these genera has varied. In 1968, Lehtinen synonymized ''Austrochilus'' and ''Thaida'' under the latter name, placing the genus in a family he called "Thaididae". However, the family name "Thaididae" is preoccupied, being first used for a family of gastropods in 1887. A single family was accepted by Forster ''et al''. in 1987, under the name "Austrochilidae". Molecular phylogenetic studies agree in placing the two genera as basal members of the Araneomorphae, although the precise details and the family placement are not yet agreed. Phylogeny One hypothesis for the phylogeny of the genera placed in the family is shown below (Austrochilidae g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gradungulidae
Gradungulidae, also known as large-clawed spiders, is a spider family endemic to Australia and New Zealand. They are medium to large-sized haplogyne spiders with three claws and two pairs of book-lungs similar to Mygalomorphae. Some species build extensive webs with an upper retreat tangle and connecting threads to scaffolding. This supports the ladder-like catching platform that is glued to the ground. ''Progradungula'', a large spider with long legs like '' Hickmania'', and ''Macrogradungula'' are the only cribellate genera of the family. Species '' Gradungula'' Forster, 1955 * ''Gradungula sorenseni'' Forster, 1955 — New Zealand '' Kaiya'' Gray, 1987 * '' Kaiya bemboka'' Gray, 1987 — New South Wales * '' Kaiya brindabella'' (Moran, 1985) — Australian Capital Territory * '' Kaiya parnabyi'' Gray, 1987 — Victoria * ''Kaiya terama'' Gray, 1987 (type species) — New South Wales ''Macrogradungula'' Gray, 1987 * ''Macrogradungula moonya'' Gray, 1987 — Queensland '' Pian ... [...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] |
Taxonomic Rank
In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species, genus, family (biology), family, order (biology), order, class (biology), class, phylum (biology), phylum, kingdom (biology), kingdom, domain (biology), domain. While older approaches to taxonomic classification were phenomenological, forming groups on the basis of similarities in appearance, organic structure and behaviour, methods based on genetic analysis have opened the road to cladistics. A given rank subsumes under it less general categories, that is, more specific descriptions of life forms. Above it, each rank is classified within more general categories of organisms and groups of organisms related to each other through inheritance of phenotypic trait, traits or features from common ancestors. The rank of any ''species'' and the description of its ''genus'' is ''basic''; which means that to iden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...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] |
Phylogenetics
In biology, phylogenetics (; from Greek language, Greek wikt:φυλή, φυλή/wikt:φῦλον, φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, Protein, protein Amino acid, amino acid sequences, or Morphology (biology), morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entelegynae
The Entelegynae or entelegynes are a subgroup of araneomorph spiders, the largest of the two main groups into which the araneomorphs were traditionally divided. Females have a genital plate ( epigynum) and a "flow through" fertilization system; males have complex palpal bulbs. Molecular phylogenetic studies have supported the monophyly of Entelegynae (whereas the other traditional subgroup, the Haplogynae, has been shown not to be monophyletic). The clade contains both cribellate and ecribellate spiders. Characterization The Entelegynae are characterized primarily by the nature of the female genital system. The ancestral ( plesiomorphic) system is found in non-entelegyne spiders, where there is a single external genital opening in the female's abdomen. One or more males inject sperm from their palpal bulbs via this opening; the sperm is usually stored in special spermathecae (absent in some spiders, e.g. ''Pholcus''). When eggs are released from the ovaries, sperm is also releas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
