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Taxonomy: Glossary

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Allotype:A specimen designated from the type series that is the opposite sex of the holotype. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Alpha taxonomy: the science of finding, describing and naming species of living or fossil organisms. The term "alpha" refers to alpha taxonomy being the first and most basic step in taxonomy. This science is supported by institutions holding collections of these organisms, with relevant data, carefully curated: such institutes include natural history museums, herbaria and botanical gardens. (Wikipedia)

Art: in this context I don't mean the Renaissance masters, or the French impressionists, but the role of subjective assessment and intuition in science, a heresy for the advocates of neo-pragmatism and extreme empiricism, but unavoidable if we are to understand something as subtle and complex as the history and nature of life on Earth. I very much like Mike Taylor's comments here on the "How to choose between specific and generic separation" in a Sauropod Vertebra Picture of the Week posting.

"At this point, I am reminded of when I used to be on a mailing list for wannabe writers...the best advice I saw on that list was from Jane MacDonald: My personal advice is don't overdo, or underdo, anything in your writing. Do it exactly right. That's my attitude to drawing genus boundaries. It is, frankly, an art; and there are no substitutes for taste, experience, judgement, familiarity with the group in question and all those other touchy-feely qualities that uber-cladists would love to find a way to abolish if they could. But they can't. There is no algorithm for this. I also think of an observation by computer scientist Bjarne Stroustrup, the inventor of the C++ programming language: "Design and programming are human activities; forget that and all is lost." The same is true of palaeontology. (And of, well, everything.)"

Available name:A name that is correctly proposed according to the International Code of Zoological Nomenclature. An available name is not necessarily the valid name. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)


Binomial nomenclature: Linnaean universal standard of biological scientific notation, according to which every species is given a distinct two-part name. The first part, think of it as like the surname, is the genus, which is capitalised, the second part the species, written completely in lower case, is like the given name. Both names are by convention written in italics (or if that is not possible, underlined, or if even that is not possible say with ASCII text, then there is an underscore character before and after the name, _like this_). So in the case of Tyrannosaurus rex, Tyrannosaurus is the genus (capital "T"), and rex (small "r") the species. Finally, the name of the discoverer of the species is added (if the species has since been given a new genus the discoverer's name is placed in brackets) along with the year of publication of the scientific paper describing that particular species. Hence (etc). This usage is not mandatory in popular and semi-technical books, but is when describing or listing species in a technical journal or a Museum. The species name can also be abbreviated by only using the first letter of the genus and a period, after which comes the species name. the species name on its own can be written as T. rex (but never "T-rex", it's not a car!). (MAK)


Category:Any rank within the classification hierarchy, e.g., family, subfamily, subspecies. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Change of rank:When a name is moved from one level of the classification system to another, e.g., when De Lotto (1955) moved Ceroplastes destructor brevicauda from the subspecies to the species rank C. brevicauda this was a change of rank. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Character: any attribute, quality, or trait of an organism used for recognizing, differentiating or classifying a taxon.(Glossary of taxonomy (Doc))

Clade: term coined by Julian Huxley, in terms of evolutionary branching and ancestry, to refer to the set of all organisms descended from a particular ancestor. In cladistics, a clade is a monophyletic group of organisms that includes all the descendants of a common ancestor as well as that ancestor itself. For example, birds, dinosaurs, pterosaurs (flying reptiles), crocodiles and their extinct relatives all form the clade Archosauria. In phenotype-based Linnaean and evolutionary systematics, clades are not always suitable as units of classification, as the crown portion of a clade may be very different from its base (compare a pelycosaur reptile to a eutherian mamal for example). The Phylocode attempts to formalise phylogenetic systematic taxonomy based on the use of clades. Contrast grade. (MAK)

Cladistics: methodology first developed by Wili Hennig and further elaborated through modern computational statistical analysis, to evaluate and reconstruct phylogenetic hypotheses in an empirical and easily verifiable manner. The results of cladistic analyses are often diagramatically represented in the form of a branching tree-like diagram, called a cladogram. As with Linnaean classification, cladistics provides a nested hierarchy in which an organism is assigned a series of names that more and more specifically locate and define it within the hierarchy. However, unlike Linnaean and evolutionary classifications, cladistics only allows monophyletic clades; it excludes ancestral (paraphyletic) groups. More

Class: In the Linnaean classification the taxonomic rank between phylum and Order. Describes a major group of organisms within a particular phylum; e.g. Insects within Arthropods or Reptiles within Chordates. (MAK) More

Classification. In biology, a classification is a system of uniting taxa into a system of interconnected units in order to reflect features uniting them. Classifications may be either artificial (built on arbitrarily-chosen features to facilitate the worker's convenience) or natural (supposedly derived from the evolutionary relationships of the taxa). Most authors would currently favour the latter, though artificial classifications may still be in use for groups of organisms (such as anamorphic fungi) in which evolutionary relationships are difficult to establish. Many groups of organisms may have different classificatory systems in use at the same time due to differing opinions between different authors, and classifications may also change as authors refine their investigations. Classification should be distinguished from nomenclature, which is the investigation of correct names for taxa. Classification and nomenclature together form taxonomy. CKT070412

Cotype: (Zoological Code) this term has been used in the past to refer to either a paratype or a syntype. Its use is now discouraged. CKT061027

Congeneric: of species that belong to the same genus

Crown group: in cladistics, a group consisting of living representatives, their ancestors back to the most recent common ancestor of that group, and all of that ancestor's descendants. The name was given by Willi Hennig as a way of classifying living organisms relative to extinct ones. more


Diagnosis: statement in words that purports to give those characters which differentiate a taxon from other taxa with which it is likely to be confused. (Glossary of taxonomy (Doc))


Emendation:An intentional change to a previously proposed name, e.g., Lindinger proposed the emendation Hemiberlesea for the armored scale Hemiberlesia indicating that it was originally improperly formed. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Epitype: (Botanical Code) a specimen designated at a later date to characterise a species, where the original type material is not sufficient to do so. The original type retains name-bearing status, and should the epitype later prove not to be conspecific, the name remains with the holotype (however, it is not uncommon for the International Association of Plant Taxonomy to conserve the common understanding of a name by setting aside the holotype in favour of the epitype). CKT061027

Evolutionary systematics, also called Evolutionary classification; application of Linnaean classification that determines the natural relationships of organisms by studying a group (generally at the rank of genus, family, or order) in detail and comparing degree of similarity and stratigraphic occurance in deep time. Has now mostly bene replaced by a rival system, cladistics. More


Family: In the Linnaean classification the taxonomic rank between order and genus (or order and tribe, tribe being a mostly botanical rank between family and genus), used to define group of related organisms. All members of a family are generally quite similar in appearance. (MAK) More


Genus: the taxonomic rank between family or tribe and species, and used to define group of closely related organisms that differ in only very minor ways. In the Linnaean system of binomial nomenclature, the genus is written in italics, with a capital letter, in front of the species name, or on its own. e.g. with Tyrannosaurus rex, the name Tyrannosaurus is the genus, and rex is the species. Occasionally subgenera and subspecies are added, so in theory it's possible to hav efour names in a binomial, although this is rarely done. In the cladistic application of vertebrate paleontology there is the tendency to allow only a single species for each genus; we have not followed this trend. (MAK) More MAK120227

Grade: an evolutionary group showing similarities in morphology, ecology or life history; a horizontal taxon consisting of transitional forms between two other taxa. (MAK). In alpha taxonomy, a grade refers to a taxon united by a level of morphological and/or physiological complexity. (from Wikipedia)

Hapantotype: (Zoological Code) for protists with complex life cycles (such as Apicomplexa), a series of specimens taken from different stages of the life cycle acting as the type. Though composed of multiple specimens, a hapantotype series is treated as a single holotype, and a lectotype may not be designated from within it. Should a hapantotype turn out to contain specimens from more than one species, specimens may be excluded from it until only conspecific ones remain. CKT061027

Holotype: a single specimen (or illustration for the Botanical Code) designated by the author in the original publication. Under the Zoological Code since 1999, any species description that does not explicitly designate a type is deemed invalid, and the species name a nomen nudum. CKT061027

Horizontal classification: as described by Simpson, a taxon based on overall similarity between its members at a particular time. All members share a common ancestry and are therefore monophyletic at that time slice, however, only the members extant at that particular time are considered. An evolutionary grade. Evolutionary systematics includes the interplay of both horizontal and vertical classification, whereas cladistics only considers vertical. (MAK) More

Homonym:One of two or more scientific names that are identical but pertain to different organisms, e.g., Eriococcus mancus Ferris, 1955 and Eriococcus mancus (Maskell, 1897); Onceropyga Ferris, 1955 and Onceropyga Turner, 1904. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)


International Code of Zoological Nomenclature: widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. The rules principally regulate:

  1. how names are correctly established in the frame of binomial nomenclature,
  2. which name has to be used in case of conflicts among various names,
  3. how names are to be cited in the scientific literature.

The rules and recommendations have one fundamental aim: to provide the maximum universality and continuity in the scientific naming of animals. The code is published by the International Commission on Zoological Nomenclature (ICZN), an organization dedicated to "achieving stability and sense in the scientific naming of animals". The rules in the Code determine what names are valid for any taxon in the family group, genus group, and species group. It has additional (but more limited) provisions on names in higher ranks. Several cladists have argued that the Linnaean based ICZN code needs to be replaced by a new cladistically-based system, the Phylocode. (Wikipedia)

Incertae sedis: A taxon of uncertain identity, classification, or phylogenetic relationship. MAK

Infrasubspecific: category or name of lower rank than subspecies, and, therefore not subject to regulation by nomenclatural Codes; e.g. form, race, variety. (Glossary of taxonomy (Doc))

Isotype: (Botanical Code) a specimen deriving from the same individual as the holotype (for instance, a second cutting from the same tree). CKT061027


Junior synonym: giving a new name to a species, supra-specific taxon, or clade which already has a scientific name. As a standard, the first applied name is the one that is used in biological and paleontological systematics. Junior synonyms are redundant and hence usually rejected in scientific nomenclature; the exception being when the more recent name is so well known that to change it would cause confusion. For example, the first named fossil which can be attributed to Tyrannosaurus rex consists of two partial vertebrae found by Edward Drinker Cope in 1892 and named Manospondylus gigas. It was only later realised that they belong to the same animal. In this case, the newer name, Tyrannosaurus rex (named by Henry Fairfield Osborn in 1905) was retained, and the older one Manospondylus gigas, rejected. If there are only two synonyms, the most recently described one is the junior synonym; if there are more than two synonyms, the junior synonyms are all but the oldest described one which is the senior synonym. (MAK, Wikipedia, ScaleNet - Terms Pertaining to Zoological Nomenclature)

Junior homonym:If there are only two homonyms, the junior homonym is the most recently described homonym; if there are more than two homonyms, the junior homonyms are all but the oldest described homonym which is the senior homonym, e.g., Eriococcus mancus Ferris, 1955 is the junior homonym and Eriococcus mancus (Maskell, 1897) is the senior homonym. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Justified emendation:An emendation that is correct according to the International Code of Zoological Nomenclature, e.g., the name susani is proposed as a patronym for a woman named Susan; according to the Code the name must be changed to susanaeand is a justified emendation. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)


Kingdom: In the Linnaean classification the highest taxonomic rank. Traditionally only included plants and animals; Whittaker-Margulis classification scheme adds three more kingdoms, and other researchers such as Thomas Cavalier-Smith have added additional kingdoms.


Lapsus calumni: (abbrev. l.c.) slip of the pen, an accidental mispelling; especially common with some of those difficult latin names. e.g. Poecilopleuron, Poecilopleurum, Poicilopleuron, and Poikilopleuron are all mispellings of the Jurasisc theropod Poekilopleuron. MAK120227

Lazarus taxon: a taxon that disappears from one or more periods of the fossil record, only to appear again later. more

Lectotype: a specimen selected from a syntype series to become the single name-bearing type of the species in order to confirm the identity of the species. The other previous syntypes become paralectotypes. CKT061027

Linnaean classification: hierarchical taxonomy developed by the 18th century Swedish botanist Carl von Linné, (Linnaeus). It was the first systematic classification of life on Earth, in which every species is given it's own binomial designation. So for example anatomically modern human beings are Homo sapiens, genus (the "family name") Homo and species (the specific name) sapiens. In contrast, Neanderthal man is Homo neanderthalensis. Linnaean classification provides a nested hierarchy of levels, each with its own specific characteristics. In this way any organism or species is grouped more and more specifically within the hierarchy. The Linnaean system was originally static, being based on creationism. In the 19th century, applied to the evolution of life and the modern synthesis it became evolutionary systematics, and was used to construct phylogenetic trees. Still foundational to modern biology, Linnaean classification is in the process of being superseded by phylogeny-based cladistic systematics. Unfortunately, this latter, with its indefinite series of nested clades, lacks the categorical simplicity and ease of use of the old Linnaean system. Some attempts have been made to integrate the two, there is disagreement over whether tthis approach is useful or not. More


Monotypic: in Linnaean classification, a higher ranked taxon that contains only a single species. e.g. Ginkgo is a monotypic genus that contains a single extant species, biloba; the family Ginkgoaceae is similarily a monotypic family. In cladistics (and especially vertebrate paleontology), allowing only the type species in that genus; all other species are given their own genera. This is in keeping with a phylocode approach (which rejects supra-specific taxa such as genera, families, phyla etc), and understandable especially when dealing with fossil taxa where there is only very limited information (sometimes all that is known of a species are a few scraps of bone) and phylogenetic placement is uncertain.


Neotype: a new type specimen designated subsequent to the original description. A neotype can only be designated if a type was not originally designated (for species published before 1999), or if the original type(s) is lost or destroyed. In a very few cases in zoological nomenclaure (such as for Coelophysis bauri) a neotype has been designated to replace an unidentifiable holotype - such an action, however, requires a Decision by the ICZN. CKT061027

New combination:When a species is transferred to a different genus for the first time. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Node-based taxon: in cladistics and phylogenetic nomenclature, all descendants of the most recent common ancestor of two specified taxa.

Nomen conservandum (abbreviation nom. cons., plural nomina conservanda – latin for "a name to be preserved") A nomen conservandum is a name that, under strict application of the appropriate code of nomenclature, should be invalid, but which the relevant commision has decided should be upheld in the interests of stability and communication. This may, for instance, involve the preservation of a well-known name for a taxon rather than its otherwise mandatory replacement with an unfamiliar or poorly-defined senior synonym. To what extent a name is conserved depends on the case - a name can be universally conserved, so that it takes priority over any non-conserved synonym, whether already known or recognised later, or it may only be conserved relative to the specific name(s) recognised in competition at the time.

For instance, the name Meganthropus africanus was established for a fossil hominid by Weinert in 1950. Later, this was synonymised with Australopithecus afarensis Johanson et al., 1978 within the genus Australopithecus. As there is already an Australopithecus africanus Dart, 1925, A. afarensis was the correct name. However, some authors have suggested that Australopithecus afarensis should be removed from Australopithecus and placed in the genus Praeanthropus. As the homonymy with Australopithecus africanus would then be removed, the technically correct name for the species would then be Praeanthropus africanus (Weinert, 1950). However, a request was made to the International Commission on Zoological Nomenclature for the preservation of the species name afarensis (nomen conservandum) due to its high public profile, and to prevent confusion with the equally well-known Australopithecus africanus. The ICZN upheld this request in 1999, meaning that even when placed in a different genus, Australopithecus afarensis remains afarensis. CKT061016

Nomen dubium (abbreviation n. d., plural nomina dubia) A nomen dubium (Latin, "doubtful name") is a taxon that has not been characterised in enough detail and whose type material is not sufficient for it to be identified. For instance, a number of dinosaur taxa named in the 1800s such as Trachodon were based on isolated teeth. Unfortunately, teeth in reptiles do not generally differ between species, meaning that fossilised teeth usually cannot be reliably identified to a particular species.

The significance of a taxon being declared a nomen dubium is often misunderstood. Contrary to popular belief, a nomen dubium is not invalid, in the way a nomen nudum is. A nomen dubium is still available for consideration in terms of synonymy and/or homonymy, and if a name previously regarded as a nomen dubium is able to identified with a better distinguished taxon that was named later, the nomen dubium is still the senior synonym, and hence the correct name for the taxon. One well-known example of this involves Allosaurus fragilis Marsh, 1877, which was suggested in the past as synonymous with Antrodemus valens Leidy, 1870, and Allosaurus appeared as Antrodemus in a number of older sources. However, Antrodemus is based on a single isolated tail bone, which is not sufficient to characterise the species. Allosaurus is currently regarded as a valid taxon, but this is because Antrodemus cannot be conclusively identified with it, not because Antrodemus is a nomen dubium. See New papers in Geobios (and nomenclatoral gripe) and follow-up messages on the Dinosaur Mailing List for an example of an argument on the appropriate application of a nomen dubium. CKT061027

Nomen nudum (abbreviation: n. n., plural nomina nuda) A nomen nudum (Latin, bare name) is a name that fails to meet the requirements for being validly published under the appropriate code of nomenclature (for instance, no published description). A nomen nudum has no official nomenclatorial standing, and does not compete for synonymy, homonymy, etc. Should a name that was previously a nomen nudum ever be validly published, its priority dates from valid publication, not from original appearance.

In these days of the internet and widespread media, nomina nuda are sometimes a significant issue (especially in vertebrate palaeontology). It is not uncommon for significant and/or interesting discoveries to be popularised in newspapers, newsgroups, etc. before their appearance in the professional literature. Any names that appear in such formats are generally nomina nuda. CKT061016

Nomen oblitum (abbreviation n. o., plural nomina oblita) A nomen oblitum (Latin, forgotten name) is one that is technically a senior synonym of another, more recent name, but which has been used little or not at all since its original publication, and which would cause confusion if resurrected. Under the International Code of Zoological Nomenclature, to qualify as a nomen oblitum a name must not have been used as valid since 1899, and the competing junior name must have appeared in at least 25 works by at least 10 authors in the immediately preceeding 50 years and over a period not exceeding 10 years. The term "nomen oblitum" has also been used in the past for names suppressed by the International Commission on Zoological Nomenclature. A name that remains in place due to its senior synonym being a nomen oblitum is called a nomen protectum. (see ICZN online for more details)

For example, the name Tyrannosaurus rex Osborn, 1905 is a junior synonym of Manospondylus gigas Cope, 1892. However, because of the obscurity of the name Manospondylus compared to the name Tyrannosaurus, the former has been declared a nomen oblitum, and Tyrannosaurus rex remains the correct name.

Unlike the ICZN, the International Code of Botanical Nomenclature does not have any provisions for automatic rejection of an old name, requiring an action by the Commission for any name suppression. It is therefore not uncommon in botanical nomenclature for old names to be resurrected. CKT061016


Order: In the Linnaean classification the taxonomic rank between class and family. Describes a major subgroup of organisms within a particular class; e.g. beetles (Order Coleoptera) within Class Insecta (or hexapoda) or lizards and snakes (order Squamata) within Reptilia. (MAK) More


Paralectotype:All of the specimens in the syntype series of a species or subspecies other than the l lectotype. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Paratype: Any specimens in the type series other than the holotype (or lectotype in the case of paralectotypes). Paratypes have no official status in determining species identity, but may have historical or practical significance (for instance, if the holotype does not show all the features useful in characterising the species). The term allotype is sometimes used for a paratype that represents the opposite sex from the holotype. CKT061027

Phylocode: abbreviation for the International Code of Phylogenetic Nomenclature, a developing draft for a formal set of rules governing phylogenetic nomenclature as used in cladistics. Its current version is specifically designed to regulate the naming of clades, leaving the governance of species names up to the rank-based codes. Unlike Linnaean-based nomenclatural codes the Phylocode does not require the use of ranks, although it does optionally allow their use. Rather than define taxa using a rank (such as genus, family, etc.) and a type specimen or type subtaxon, the content of taxa are delimited using a definition that is based on phylogeny (i.e., ancestry and descent) and uses specifiers (e.g., species, specimens, apomorphies) to indicate actual organisms. The defined taxon, then, is that ancestor and all of its descendants. (Wikipedia)

Phylogenetic nomenclature, (also Phylogenetic classification, Phylogenetic taxonomy, sometimes abbrviated as PN. Classification and taxonomy based on cladistic principles, proposed as a rank-free alternative to the Linnaean system of classification, and using instead an indefinite series of nested clades. The Phylocode is intended as a formal set of rules for PN. (MAK)

Phylogeny: the study of the evolutionary relationships among groups of organisms, often illustrated with a branching diagram called a tree. Phylogeny as a branch of science was first developed by Ernst Haeckel in the 1860s More recently, phylogeny and phylogenetics have been used as synonyms for cladistics and molecular evolution. MAK120227

Phylum: In the Linnaean classification the rank between kingdom and class, one of the highest levels of taxonomic classification, used to define major groups of organisms; e.g. molluscs, arthropods, echinoderms, chordates. The term Phylum was not in Linneaus' original classification system, but was added later by Haeckel. (MAK, Wikipedia)



Rank: the hierarchical level of a supra-specific taxon, according to the Linnaean approach to classification. The eight ranks are kingdom, phylum (added by Haeckel), class, order, family, tribe (used mostly in botany, much more rarely in zoology and paleontology), genus, and species, plus optional intermediate grades represented by the suffixes super-, sub- and infra- (MAK)

Replacement name:A name that is assigned to replace a name that is a junior homonym, e.g., Onceropyga Turner, 1904 is the valid name and Onceropyga Ferris, 1955 is the junior homonym and must be replaced; Hoy (1963) proposed the replacement name Oregmopyga. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)


Senior homonym:The oldest described homonym, e.g., Onceropyga Turner, 1904 is the senior homonym and Onceropyga Ferris, 1955 is the junior homonym. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Senior synonym:The oldest synonym, e.g., Apiomorpha pharetrata Scharder, 1863 is the senior synonym and A. nux Fuller, 1896 is the junior synonym. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Species: The most fundamental unit of evolutionary biology, according to which one type of organism is considered a distinct type from another. This highly controversial term given a variety of definitions by biologists, hence Biological Species Concept, cladistic species concept, ecological species concept, phenetic species concept, and recognition species concept, and many more MAK120227

Splitters versus lumpers: Philosophical conflict among taxonomists, as regards ranking of a taxon. As the name indicates, splitters tend to divide varying individuals from a single species among several different species. Lumpers tend to include specimens or populations normally attributed to different species in a single species . The same principle can be applied at the supra-specific level. (MAK111018)

The earliest use of these terms was apparently by Charles Darwin himself, in a letter to J. D. Hooker in 1857. "(Those who make many species are the 'splitters,' and those who make few are the 'lumpers.')" They were introduced more widely by the biologist George G. Simpson in his 1945 work "The Principles of Classification and a Classification of Mammals." As he put it, "splitters make very small units â€"-their critics say that if they can tell two animals apart, they place them in different genera... and if they cannot tell them apart, they place them in different species. Lumpers make large units - their critics say that if a carnivore is neither a dog nor a bear, they call it a cat." - Simpson 1945. (From Wikipedia)

Stem-based taxon (or clade): in cladistics and phylogenetic nomenclature, all species, living or extinct, that share a more recent common ancestor with a specified species than with other species or taxon

Subgenus: A group of species less inclusive than a genus. The subgenus name is written in italics and brackets, after the genus but before the species. It may be the same as or different to the genus, e.g. Cypraea (Cypraea) tigris Linnaeus, the tiger cowrie, belongs to the subgenus Cypraea of the genus Cypraea. However, it is not mandatory, or even customary, when giving the name of a species, to include the subgeneric name. One paleo artist and author of popular books on dinosaurology, Greg Paul, sometimes coins subgenera, although this practice is otherwise very rarely used in vertebrate paleontology MAK120227,

Subspecies: The smallest taxonmic rank; a group of organisms less inclusive than a species. The term is usually applied to populations or groups within a species that have distinct forms or characteristics and live in a restricted geographic area. In contrast to the species, members of different subspecies can usually interbreed and give rise to fertile offspring. The subspecies name is written in italics after the species, and may or may not be the same as the species name. e.g. The Cape Mountain Zebra is referred to as Equus zebra zebra, as distinguished from Hartmann's Mountain Zebra, Equus zebra hartmannae

Supra-specific taxon: a taxon above the species level: anything from subgenus and genus upwards (family, order, etc). Useful for understanding biotic diversity through time and large scale patterns of evolution. Recognised by evolutionary systematics, but not by cladistics. See also rank. (MAK)

Synonym. In taxonomy, the term synonyms is used to refer to two or more names referring to the same taxonomic entity. It is a general principle of taxonomy that any taxon can have only one valid name - usually, this is the oldest name available (the senior synonym, as opposed to a junior synonym) if there is more than one (but see Nomen oblitum for one example of where this rule may be suspended). A list of names used to refer to a taxonomic entity is referred to as a synonymy.

Synonyms may be either objective or subjective. Objective synonyms have the same type as each other, and as such will always refer to the same taxon. Subjective synonyms have different types, and authors may differ as to whether they represent the same taxon or not. In synonymies presented on, we have generally distinguished between the two classes by using "=" for objective synonyms and "incl." for subjective synonyms. CKT070221

Synonymy:A section of a systematic presentation about an organism that lists all of the names that have been used for the organism including synonyms, new combinations, misidentifications, etc. In some cases this section may include only true synonyms. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Syntype: The series of specimens used to describe a species or subspecies when the author did not include a holotype ( ScaleNet - Terms Pertaining to Zoological Nomenclature). Where the original description was based on a number of specimens, some or all of them may hold equal status as type specimens. Should a syntype series turn out to contain examples of more than one species, a subsequent reviser may designate a lectotype. CKT061027

Systematics: The field of science dealing with the diversity of life and the evolutionary relationships of life's component organisms. - (modified from ScaleNet - Terms Pertaining to Zoological Nomenclature)

Systematic biology, taxonomy, and scientific classification are often confused and used interchangeably. However, taxonomy is more specifically the identification, description, and naming (i.e. nomenclature) of organisms, classification focuses on placing organisms within hierarchical groups that show their relationships to other organisms, and systematics alone deals specifically with relationships through time, and can be synonymous with phylogenetics, broadly dealing with the inferred evolutionary hierarchy of organisms. (MAK, Wikipedia)

Systematic paleontology: organising or classifying fossil organisms (paleontology) according to the principles of systematics. (MAK)


Taxon: (plural: taxa) a group of organisms, considered to be a unit, and which generally has been formally named with a scientific (Latin or Greek) proper name and a rank. Defining what belongs or does not belong to such a taxonomic group is done by a taxonomist with the science of taxonomy. It is not uncommon for one taxonomist to disagree with another on what exactly belongs to a taxon, or on what exact criteria should be used for inclusion. Traditionally, a taxon is given a formal or scientific name, which is governed by one of the Nomenclature Codes, which sets out rules to determine which scientific name is correct for that particular grouping. Generally, a good taxon as one that reflects evolutionary relationships. (modified from Wikipedia)

Taxonomic inflation: Pejorative term for what is perceived to be an excessive increase in the number of recognised taxa in a given context, due not to the discovery of new taxa but rather to putatively arbitrary changes to how taxa are delineated. For example, a subspecies may be elevated to species rank, through the arbitrary decision that the differences between the various taxa warrant distinguishing them at species rank. (From Wikipedia). Another form of taxonomic, or rank, inflation is elevating subfamilies to families, families to superfamilies or orders, and so on, which tends to be an on-going process as more taxa are discoevred. For eaxmple in the late 1980s Carcharodontosaur theropods were included under the Allosauridae, now they are given their own family. MAK011227

Taxonomy: The field of science converned with discovering, describing, clasisfying, and naming organisms. It is supported by institutions holding collections of these organisms, with relevant data, carefully curated: such as Natural History Museums, Herbaria and Botanical Gardens. Taxonomy uses taxonomic units, known as taxa (singular taxon). In addition, the word is also used as a count noun: a taxonomy, or taxonomic scheme, is a particular classification ("the taxonomy of ..."), arranged in a hierarchical structure. The roots of taxonomy go back to Aristotle at least, although it was only really developed as a modern science by Linnaeus. Modern approaches to taxonomy follow the same principle of organising and understanding the natural world. These taxonomies fall into three major schools: phenetic, phylogenetic (cladistic), and evolutionary. Each of these pertains to a different phylogenetic methodology, a different way of mapping out the history and evolution of life on Earth .See also Alpha taxonomy , cladistics, Linnaean classification, Systematics. MAK120229

Topotype:One or more specimens collected at the same location as the type series regardless of whether they are part of the type series. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Tribe: In the Linnaean classification a mostly botanical taxonomic rank between family and genus. With the multiplication of ranks in linnaean-cladistic hybrid taxonomies, "tribe" has been used more widely. (MAK) More

Type: The term "type" is tied in biological nomenclature to a very specific concept - that of a designated specifier that provides the definitive concept of a given taxon. For instance, when describing a new species, the author(s) is required to name the specimen or one of the specimens used as the type specimen. The name for the new species then becomes indelibly tied to that specimen, and should any confusion ever arise as to the identity of the species (for instance, if it turns out that two or more species have been mistaken for one, or if the published description turns out to omit some feature[s] required for identification), examination of the type specimen should (hopefully) resolve these issues. Similarly, at higher levels, each genus requires a type species, and each family requires a type genus. See International Code of Zoological Nomenclature Online for more information relevant to animals, and International Code of Botanical Nomenclature for plants. Different nomenclatorial codes may differ in the terminology used. CKT061027

A number of terms are in use to refer to different classes of types, including holotype, (the most important, as it used to define a species), allotype, epitype:, hapantotype, isotype, lectotype, neotype, paratype , syntype, topotype, type series and type strain MAK120227

Type genus:A genus that has been selected as the standard bearer of a tribe, family, or superfamily and provides the stem of the family-group name. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Type locality:The geographic location where the primary type was collected. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Type series: the total group of specimens used in the original description. Ideally, one specimen is the holotype and the remainder paratypes, but if no holotype has been designated, the entire type series become syntypes. CKT061027

Type species:A species that has been selected as the standard bearer of a genus or subgenus. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Type strain: (Bacteriological Code) For prokaryotes, the type is not a preserved specimen, but an isolated culture. The Bacteriological Code of Nomenclature requires that cultures of the type strain be deposited in at least two separate institutes' culture stores. CKT061027


Unavailable name:A name that is incorrectly proposed according to the International Code of Zoological Nomenclature. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)

Unjustified emendation:An emendation that is incorrect according to the International Code of Zoological Nomenclature, e.g., the generic name Hemiberlesea Lindinger is an incorrect change of Hemiberlesia Cockerell according to the Code and is an unjustified emendation. - (ScaleNet - Terms Pertaining to Zoological Nomenclature)


Valid name:The correct name of an organism, e.g., if Apiomorpha nux Fuller, 1896 and A. pharetrata Scharder, 1863 apply to the same species (and therefore are synonyms), then by the law of priority (the oldest name prevails) A. pharetrata Scharder, 1863 is the valid name.

Vertical classification: as described by Simpson, a taxon based on ancestor and descendant (phylogenetic) relationship between its members, a clade. (MAK) More


Wastebasket taxon: a taxon that includes all species or groups that cannot be easily or conveniently placed elsewhere, e.g., for a while all large theropod dinosaurs that could not be included under the Ceratosauridae, Allosauridae or Tyrannosauridae were named Megalosaurus.




Zombie taxon, Zombie effect: Before the zombie craze took over geek/nerd culture (perhaps as a counterpole to the excessively feminine/romantic "supernatural romance" vampire story) the technical term for a fossil of this sort was term "reworked". Refers to a fossil such as a dinosaur tooth that was washed out of sediments and re-deposited in rocks and/or sediments millions of years younger. This basic mistake in the interpretation of the age of the fossil leads to its title. The discovered fossil was at some point mobile (or "walking") while the original animal or plant had long been dead. (MAK, Wikipedia)

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