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Informal Group (taxonomy)
An informal group in taxonomy is a taxonomic rank that is not well defined. This type of group can be paraphyletic or polyphyletic but is kept for ease, pending new systems of classification. In zoology Examples can be found in the classification of gastropods: Opisthobranchia, Sorbeoconcha, Hypsogastropoda, and Ptenoglossa are informal groups nearby the level of the order. In human taxonomy, the informal taxonomic rank of race is variously considered equivalent or subordinate to the rank of subspecies. In botany An alliance An alliance is a relationship among people, groups, or states that have joined together for mutual benefit or to achieve some common purpose, whether or not explicit agreement has been worked out among them. Members of an alliance are called ... is also considered an informal grouping of species,A taxonomic revision of Hebe informal group “ Connatae” (Plantaginaceae∗), based on morphology and flavonoid chemistry. Alison V. Kellow, Mich ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy (biology)
In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a more inclusive group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain, kingdom, phylum (''division'' is sometimes used in botany in place of ''phylum''), class, order, family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, as he developed a ranked system known as Linnaean taxonomy for categorizing organisms and binomial nomenclature for naming organisms. With advances in the theory, data and analytical technology of biological systematics, the Linnaean system has transformed into a system of modern biological classification intended to reflect the ... [...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, order, class, phylum, kingdom, 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 traits or features from common ancestors. The rank of any ''species'' and the description of its ''genus'' is ''basic''; which means that to identify a particular organism, it is usually not necessary to specify ranks other than these first two. Consider a parti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyletic
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic group (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term was coined by Willi Hennig to apply to well-known taxa like Reptilia ( reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor, including all extant reptiles as well as the extinct synaps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphyletic
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly .. ource for pronunciation./ref> It is contrasted with monophyly and paraphyly. For example, the biological characteristic of warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds; "warm-blooded animals" is therefore a polyphyletic grouping. Other examples of polyphyletic groups are algae, C4 photosynthetic plants, and edentates. Many taxonomists aim to avoid homoplasies in grouping taxa together, with a goal to identify and eliminate groups that are found to be polyphyletic. This is often the stimulus for major revisions of the classification schemes. Researchers concerned more with ecology than with systema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthobranchia
Opisthobranchs () is now an informal name for a large and diverse group of specialized complex gastropods which used to be united in the subclass Opisthobranchia. That taxon is no longer considered to represent a monophyletic grouping. Euopisthobranchia is a taxon containing a revised collection of opisthobranchs, and that taxon is considered monophyletic. Euopisthobranchia does not include some "traditional" opisthobranchs such as the Sacoglossa and the Acochlidiacea. The subclass Heterobranchia now contains all the species which used to be assigned to Opisthobranchia, plus all the species in the Pulmonata. The subclass Opisthobranchia included species in the order Cephalaspidea (bubble shells and headshield slugs), the sacoglossans, anaspidean sea hares, pelagic sea angels, sea butterflies, and many families of the Nudibranchia. ''Opisthobranch'' means "gills behind" (and to the right) of the heart. In contrast, ''Prosobranch'' means ''gills in front'' (of the hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorbeoconcha
Sorbeoconcha is a taxonomic clade of snails, i.e. gastropods, mainly marine species with gills and opercula, within the clade Caenogastropoda. The taxon Sorbeoconcha was named by Winston Ponder and David R. Lindberg in 1997. Taxonomy 1997 taxonomy According to the older taxonomy by Ponder and Lindberg the suborders within the order Sorbeoconcha are: * Discopoda P. Fischer, 1884 * Murchisoniina Cox & Knight, 1960 * Hypsogastropoda Ponder & Lindberg, 1997 * Cerithiimorpha Golikov & Starobogatov, 1975 2005 taxonomy In the taxonomy by Bouchet & Rocroi (2005),Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005. ''Classification and nomenclator of gastropod families''. Malacologia: International Journal of Malacology, 47(1-2). ConchBooks: Hackenheim, Germany. . . 397 pp. http://www.vliz.be/Vmdcdata/imis2/ref.php?refid=78278 the clade Sorbeoconcha was declared a taxon of unspecified rank, within the clade Caenogastropoda. It c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypsogastropoda
Hypsogastropoda is a clade containing marine gastropods within the clade Caenogastropoda. MolluscaBase eds. (2021). MolluscaBase. Hypsogastropoda. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=411667 on 2022-01-01 Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005. ''Classification and nomenclator of gastropod families''. Malacologia: International Journal of Malacology, 47(1-2). ConchBooks: Hackenheim, Germany. . . 397 pp. http://www.vliz.be/Vmdcdata/imis2/ref.php?refid=78278 This clade is considered by the database WoRMS as an alternate representation This clade contains two clades and one informal group: * Clade Littorinimorpha * Informal group Ptenoglossa * Clade Neogastropoda Neogastropoda is an order of sea snails, both freshwater and marine gastropod molluscs. Description The available fossil record of Neogastropoda is relatively complete, and supports ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptenoglossa
The Ptenoglossa is an informal taxonomic group of sea snails. This group was considered paraphyletic or polyphyletic by Ponder and Lindberg (1997) in their classification of gastropod molluscs. The database WoRMS considers this suborder as belonging to the order (unassigned Caenogastropoda) (temporary name) MolluscaBase eds. (2020). MolluscaBase. Ptenoglossa. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=411725 on 2020-08-02 Taxonomy *Superfamily Epitonioidea **Family Epitoniidae **Family Janthinidae **Family Nystiellidae *Superfamily Eulimoidea **Family Eulimidae **Family Aclididae *Superfamily Triphoroidea **Family Triphoridae **Family Cerithiopsidae **Family Newtoniellidae Newtoniellidae is a family of minute sea snails, marine gastropod mollusks or micromollusks in the superfamily Triphoroidea Triphoroidea is a superfamily of minute sea snails, marine gastropod molluscs or micromolluscs within t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order (biology)
Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Taxonomy
Human taxonomy is the classification of the human species (systematic name ''Homo sapiens'', Latin: "wise man") within zoological taxonomy. The systematic genus, ''Homo'', is designed to include both anatomically modern humans and extinct varieties of archaic humans. Current humans have been designated as subspecies ''Homo sapiens sapiens'', differentiated, according to some, from the direct ancestor, ''Homo sapiens idaltu'' (with some other research instead classifying ''idaltu'' and current humans as belonging to the same subspecies). Since the introduction of systematic names in the 18th century, knowledge of human evolution has increased drastically, and a number of intermediate taxa have been proposed in the 20th and early 21st centuries. The most widely accepted taxonomy grouping takes the genus ''Homo'' as originating between two and three million years ago, divided into at least two species, archaic ''Homo erectus'' and modern ''Homo sapiens'', with about a dozen furthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Race (biology)
In biological taxonomy, race is an informal rank in the taxonomic hierarchy for which various definitions exist. Sometimes it is used to denote a level below that of subspecies, while at other times it is used as a synonym for subspecies. It has been used as a higher rank than strain, with several strains making up one race. Races may be genetically distinct populations of individuals within the same species, Republished without known revision several times since 1999, and originally published as: or they may be defined in other ways, e.g. geographically, or physiologically. Genetic isolation between races is not complete, but genetic differences may have accumulated that are not (yet) sufficient to separate species. The term is recognized by some, but not governed by any of the formal codes of biological nomenclature. Taxonomic units below the level of subspecies are not typically applied to animals. Other terms In botany, the Latin words ''stirps'' and ''proles'' were trad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
