Taxonomy: Glossary

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

J.

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)

K.

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.

L.

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

M.

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.

N.

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

O.

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

P.

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)

Q.

R.

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)

S.

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)

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 Palaeos.org, 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)

T.

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

U.

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)

V.

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

W.

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.

X.

Y.

Z.

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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