Wiktionary:Taxonomic names

This is an essay. It is not a policy or guideline; it merely reflects the opinions of some of its author(s). Please update the page as needed, or discuss it on the talk page.

Taxonomic names have peculiar features that deserve special consideration. Specifically, they are translingual, usable in any language that can accommodate Latin script and actually in use in scientific and other discourse in many languages. The names form a hierarchical structure, that is, however, subject to revision. Official bodies determining the status of names and of the hierarchical structure, which determinations strongly influence usage. Although taxonomic names have advantages and are widely known, vernacular names are often more common in each language for those species and genera encountered in the course of everyday life.

Any term which occurs only in taxonomic names is listed as Translingual, not Latin.

Information structure of definitions

Information about taxonomic names is relatively highly structured. That structure may make it easier to use templates to facilitate the improvement of entries. Some of that structure follows:

Essential for stub

Taxonomic level (argument 1 in {{taxon}} or level=) [mandatory]
Placement in taxonomic hierarchy (arguments 2 and 3 in {{taxon}} and, optionally for a stub entry, Hyponyms/Hypernyms/Coordinate terms semantic relations headers).
1. Taxa below the rank of family, at least down to species level, should use "family" as argument 2 if possible. Families are more stable and widely used than groupings such as subfamily, supertribe, tribe, subtribe, subgenus, and section. Furthermore the genus name is included as part of binomial and trinomial names and need not be repeated as part of the definition as well.
2. Taxa below the rank of order and of family rank or higher should use "order" as argument 2 if possible. Orders are relatively stable.
3. Taxa of higher rank should use class, phylum, or kingdom based on which a user would recognize and find useful.
4. In some cases other ranks may be appropriate based on their recognizability and utility.
5. Some taxa may be of such specialized use that they need to be defined relative to a hypernym other than one recommended above.
Links to Wikipedia ({{pedia}}), Wikispecies ({{specieslite}}), WikiCommons ({{comcatlite}}) under External links header.

Valuable additional information of highest priority

Gender for taxa at rank of genus, species, subspecies, etc
Etymology or {{rfe|mul}}
Image or {{rfi}}, especially for genus, species, or subspecies.
Photo or drawing that illustrates, for example, a rationale for the Etymology or vernacular name
English vernacular name (vern=) [may not exist or may only differ by capitalization or trivial morphological difference]
Additional links to taxonomy databases (using "R:" templates in Category:Taxonomic name template) or dictionaries, especially using {{R:Century 1911}}, {{R:Webster 1913}}, and {{R:OneLook}}.

Further information to improve entry quality, especially for a species or subspecies entry.

Type status (type for hyponyms?, type) [to be shown in Hyponyms, optionally for Hypernyms]
Status of name (synonym, basionym, etc) [junior synonymy eliminates need for full def., some others indicate reason for obsolescence, archaicism]
Range (range=) ("cosmopolitan" unmarked) [useful for soliciting translation requests]
Extinct or not (x=1*) ("extant" unmarked) [use of † to mark extinct?].
Differentia (?) (diff=) [relative to natural or taxonomic hypernym?]
Importance to humans {imp=, optional)
Phylogenetic status (monophyletic, paraphyletic*, polyphyletic*) (phyl=)
"Natural" hyponym [natural to whom?] (hyp=)

Abbreviations in parentheses are not yet implemented. Items with "*" would be marked.

Arguably, items 1, 2, and 3 are more clearly conveyed under the Hypernyms and Hyponyms categories. Though it is standard lexicographic practice to include a hypernym in a definition, in the case of taxonomic names, some of the hyponyms have no meaning to normal users and little to others, being either obscure themselves or mere morphological relatives of the definiendum. Thus our use of {{taxon}}, as structured, arguably has taken us down a wrong track.

Example

See [[Taxodium]] for an example of a pretty good taxonomic name entry for a genus, but which lacks "further information".

Traditional Linnaean taxonomy

From the time of Linnaeus in the second half of the 18th century, a formal system of naming living things based on more or less apparent characteristics developed. See Linnaean taxonomy and Biological classification at Wikipedia.

As it developed before the Darwin's theory of evolution was published, developed, and accepted, it is not necessarily consistent with that theory. This system is still useful in grouping specimens for further taxonomic analysis.

Modern taxonomy

Modern taxonomy strives to make all taxa into groups that are descent groups called clades. See Evolutionary taxonomy at Wikipedia. Ideally from a phylogenetic point of view, Wiktionary definitions of all taxonomic groups that are clades would have phylogenetic definitions. However, such definitions often do not meet the needs of normal users so images and definitions that explain why a given taxon is of interest to humans are often more helpful.

Phylogenetic definitions of clade names

Phylogenetic nomenclature ties names to clades, groups consisting solely of an ancestor and all its descendants. All that is needed to specify a clade, therefore, is to designate the ancestor. There are a number of ways of doing this. Commonly, the ancestor is indicated by its relation to two or more specifiers (species, specimens, or traits) that are mentioned explicitly. The diagram shows three common ways of doing this.

The three most common ways to define the name of a clade: node-based, branch-based and apomorphy-based definition. The tree represents a phylogenetic hypothesis on the relations of A, B and C.

A node-based definition could read: "the last common ancestor of A and B, and all descendants of that ancestor". Thus, the entire line below the junction of A and B does not belong to the clade to which the name with this definition refers.

Example: The sauropod dinosaurs consist of the last common ancestor of Vulcanodon (A) and Apatosaurus (B)^[1] and all of that ancestor's descendants. This ancestor was the first sauropod. C could include other dinosaurs like Stegosaurus.

A branch-based definition, often called a stem-based definition, could read: "the first ancestor of A which is not also an ancestor of C, and all descendants of that ancestor". Thus, the entire line below the junction of A and B (other than the bottommost point) does belong to the clade to which the name with this definition refers.

Example: The rodents consist of the first ancestor of the house mouse (A) that is not also an ancestor of the eastern cottontail rabbit (C) together with all descendants of that ancestor. Here, the ancestor is the very first rodent. B is some other descendant, perhaps the red squirrel.

An apomorphy-based definition could read: "the first ancestor of A to possess trait M that is inherited by A, and all descendants of that ancestor". In the diagram, M evolves at the intersection of the horizontal line with the tree. Thus, the clade to which the name with this definition refers contains that part of the line below the last common ancestor of A and B which corresponds to ancestors possessing the apomorphy M. The lower part of the line is excluded. It is not required that B have trait M; it may have disappeared in the lineage leading to B.

Linguistic content

Taxonomic names have less linguistic content than entries for natural language terms. Nevertheless, all taxonomic names have etymologies, they are spoken, and they have gender and number, inherited from or imitating Latin.

Semantics

Although taxonomic names have proscribed meanings, those meanings can change over time, both in terms of circumscription (species etc included) and criteria for membership. Some terms lose their official status, but remain in use in the relevant translingual communities of scientists in some way. It is extremely difficult to characterize all the meanings a taxonomic name may have had over time. To the extent that the definition may depend on other taxonomic names, either hyponyms or hypernyms, ancestors or descendants, which themselves change over time, it can be a difficult research project to determine what a given author meant in using a term. Such concepts as basionym and type (eg, type species, type genus) are helpful in providing relatively stable reference points for related taxa.

Etymology

Multipart names, ie, those below genus, need not have etymologies distinct from their component words. However it can be useful to characterize why the epithet (specific or subspecific) is applied, especially if it is not obvious from an image in the entry, from the epithet itself, or in combination.

Genera usually have names originating in other languages, most often Latin and Greek, but increasingly from indigenous languages in their native range. Some are Latinizations of the names of scientists. Some are formed by suffixation from the names of other genera.

Specific epithets can be of Latin or Greek origin, be eponymous, etc. They can be adjectives, possessive forms of nouns, or nouns used attributively.

Names above the level of genus, at least to the level of order, often are formed from a genus name and a suffix, plural in form.

Many higher level names have other Latinate derivations.

Pronunciation

In principle, the pronunciation and its transcription into IPA could differ by the native language of the speaker.

Gender and number

The nouns all have gender and number, but the importance is highest for genus names, for which the specific epithet, if an adjective or participle used as an adjective, should be in agreement. Note that many specific epithets are in the form of the Latin genitive of nouns or of nouns used attributively, which therefore need not be in agreement.

Genus and species names are singular in form. All higher taxa are plural in form.