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Serikodiastida
Tetrapulmonata is a non-ranked supra-ordinal clade of arachnids. It is composed of the extant orders Thelyphonida (whip scorpions), Schizomida (short-tailed whip scorpions), Amblypygi (tail-less whip scorpions) and Araneae (spiders). It is the only supra-ordinal group of arachnids that is strongly supported in molecular phylogenetic studies. Two extinct orders are also placed in this clade, Haptopoda and Uraraneida. In 2016, a newly described fossil arachnid, '' Idmonarachne'', was also included in the Tetrapulmonata; it has not been assigned to an order. Etymology It receives its name from the presence of paired book lungs occupying the second and third opisthosomal segments, although the posterior pair is absent in Schizomida and most araneomorph spiders. Previous synonyms of this lineage are rejected; "Caulogastra Pocock, 1893" refers to pedicel, which is symplesiomorphic for the lineage and convergent with Solifugae, and "Arachnidea Van der Hammen, 1977" is easily con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uraraneida
Uraraneida is an extinct order of arachnids, known from fossils of Middle Devonian, Permian and possibly Cretaceous age. Two genera of fossils have been definitively placed in this order: ''Attercopus'' from the Devonian of United States and ''Permarachne'' from the Permian of Russia. In 2018, a third genus ''Chimerarachne'', from the Cretaceous of Myanmar was proposed to belong to this group, but this placement is disputed. When the first fossils were found, they were identified as spiders, but now constitute the Uraraneida, a separate but closely related group. Characteristics The first fossil now placed in the order was found in Gilboa, New York. In 1987, it was initially tentatively placed in the extinct order Trigonotarbida and named ''Gelasinotarbus''? ''fimbriunguis''. Later, partly on the basis of a supposed spinneret, it was identified as a spider and named ''Attercopus fimbriunguis''. Further specimens of this species were found, and when examined in detail, along with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Idmonarachne
''Idmonarachne'' is an extinct genus of arachnids, containing one species, ''Idmonarachne brasieri''. It is related to uraraneids and spiders. Fossil A fossil assigned to this genus was found at Montceau-les-Mines, France, in ironstone concretion deposits of Late Carboniferous ( Stephanian) age, about 305–299 million years old. Montceau fossils are generally preserved in such a way that fine details can be observed and three-dimensional analysis is possible. In the case of ''Idmonarachne'', computerized tomography was used to construct a "virtual fossil". Description The total body length of the fossil is around 10.5 mm, with the preserved part of the carapace of the cephalothorax about 5 mm long and the opisthosoma (abdomen) about 6 mm long. The eight walking legs are more-or-less uniform in appearance, with the fourth leg longest at about 8.5 mm and the first shortest at about 6.5 mm. The legs terminate in at least two claws. The two pedipalps are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubbardia Pentapeltis
''Hubbardia pentapeltis'' is a species of short-tailed whipscorpion in the family Hubbardiidae Hubbardiidae is a family of arachnids, superficially resembling spiders. It is the larger of the two extant families of the order, Schizomida, and is divided into two subfamilies. The family is based on the description published by Orator F. Co .... References Further reading * External links * Schizomida Articles created by Qbugbot Animals described in 1899 {{arachnid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxon
In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigonotarbid
The order Trigonotarbida is a group of extinct arachnids whose fossil record extends from the late Silurian to the early Permian (Pridoli to Sakmarian).Dunlop, J. A., Penney, D. & Jekel, D. 2020A summary list of fossil spiders and their relatives In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 20.5 These animals are known from several localities in Europe and North America, as well as a single record from Argentina. Trigonotarbids can be envisaged as spider-like arachnids, but without silk-producing spinnerets. They ranged in size from a few millimetres to a few centimetres in body length and had segmented abdomens (opisthosoma), with the dorsal exoskeleton ( tergites) across the backs of the animals' abdomens, which were characteristically divided into three or five separate plates. Probably living as predators on other arthropods, some later trigonotarbid species were quite heavily armoured and protected themselves with spines and tube ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arachnid
Arachnida () is a class of joint-legged invertebrate animals ( arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroons. Almost all adult arachnids have eight legs, although the front pair of legs in some species has converted to a sensory function, while in other species, different appendages can grow large enough to take on the appearance of extra pairs of legs. The term is derived from the Greek word (''aráchnē'', 'spider'), from the myth of the hubristic human weaver Arachne, who was turned into a spider. Almost all extant arachnids are terrestrial, living mainly on land. However, some inhabit freshwater environments and, with the exception of the pelagic zone, marine environments as well. They comprise over 100,000 named species, of which 47,000 are species of spiders. Morphology Almost all adult arachnids have eight legs, unli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solifugae
Solifugae is an order of animals in the class Arachnida known variously as camel spiders, wind scorpions, sun spiders, or solifuges. The order includes more than 1,000 described species in about 147 genera. Despite the common names, they are neither true scorpions (order Scorpiones), nor true spiders (order Araneae). Most species of Solifugae live in dry climates and feed opportunistically on ground-dwelling arthropods and other small animals. The largest species grow to a length of , including legs. A number of urban legends exaggerate the size and speed of the Solifugae, and their potential danger to humans, which is negligible. Anatomy Solifuges are moderately small to large arachnids (a few millimeters to several centimeters in body length), with the larger species reaching in length, including legs. In practice, the respective lengths of the legs of various species differ drastically, so the resulting figures are often misleading. More practical measurements refer prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas ''homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to paralle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symplesiomorphy
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and synapomorphy, all mean a trait shared between species because they share an ancestral species. Apomorphic and synapomorphic characteristics convey much information about evolutionary clades and can be used to define taxa. However, plesiomorphic and symplesiomorphic characteristics cannot. The term ''symplesiomorphy'' was introduced in 1950 by German entomologist Willi Hennig. Examples A backbone is a plesiomorphic trait shared by birds and mammals, and does not help in placing an animal in one or the other of these two clades. Birds and mammals share this trait because both clades are descended from the same far distant ancestor. Other clades, e.g. snakes, lizards, turtles, fish, frogs, all have backbones and none are either birds no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pedicel (spider)
The anatomy of spiders includes many characteristics shared with other arachnids. These characteristics include bodies divided into two tagmata (sections or segments), eight jointed legs, no wings or antennae, the presence of chelicerae and pedipalps, simple eyes, and an exoskeleton, which is periodically shed. Spiders also have several adaptations that distinguish them from other arachnids. All spiders are capable of producing silk of various types, which many species use to build webs to ensnare prey. Most spiders possess venom, which is injected into prey (or defensively, when the spider feels threatened) through the fangs of the chelicerae. Male spiders have specialized pedipalps that are used to transfer sperm to the female during mating. Many species of spiders exhibit a great deal of sexual dimorphism. External anatomy Spiders, unlike insects, have only two main body parts ( tagmata) instead of three: a fused head and thorax (called a cephalothorax or prosoma) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym (taxonomy)
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called ''Pinus abies''. This name is no longer in use, so it is now a synonym of the current scientific name, '' Picea abies''. * In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refers to a taxon at that rank - for example, the name ''Papilio prorsa'' Linnaeus, 1758 is a junior synonym of ''Papilio levana'' Linnaeus, 1758, being names for different seasonal forms of the species now referred to as ''Araschnia l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
