In biology, a homonym is a name for a
taxon
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
that is identical in spelling to another such name, that belongs to a different taxon.
The rule in the
International Code of Zoological Nomenclature
The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the ...
is that the first such name to be published is the senior homonym and is to be used (it is "
valid"); any others are junior homonyms and must be replaced with new names. It is, however, possible that if a senior homonym is archaic, and not in "prevailing usage," it may be declared a ''
nomen oblitum
In zoological nomenclature, a ''nomen oblitum'' (plural: ''nomina oblita''; Latin for "forgotten name") is a disused scientific name which has been declared to be obsolete (figuratively 'forgotten') in favour of another 'protected' name.
In its p ...
'' and rendered unavailable, while the junior homonym is preserved as a ''
nomen protectum
In zoological nomenclature, a ''nomen oblitum'' (plural: ''nomina oblita''; Latin for "forgotten name") is a disused scientific name which has been declared to be obsolete (figuratively 'forgotten') in favour of another 'protected' name.
In its p ...
''.
:For example:
:*
Cuvier proposed the genus ''Echidna'' in 1797 for the
spiny anteater.
:*However,
Forster had already published the name ''Echidna'' in 1777 for a genus of
moray eel
Moray eels, or Muraenidae (), are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are f ...
s.
:*Forster's use thus has priority, with Cuvier's being a junior homonym.
:*
Illiger
Johann Karl Wilhelm Illiger (19 November 1775 – 10 May 1813) was a German entomologist and zoologist.
Illiger was the son of a merchant in Braunschweig. He studied under the entomologist Johann Hellwig, and later worked on the zoological coll ...
published the replacement name ''Tachyglossus'' in 1811.
Similarly, the
(ICN) specifies that the first published of two or more homonyms is to be used: a later homonym is "
illegitimate
Legitimacy, in traditional Western common law, is the status of a child born to parents who are legally married to each other, and of a child conceived before the parents obtain a legal divorce. Conversely, ''illegitimacy'', also known as ''b ...
" and is not to be used unless
conserved (or sanctioned, in the case of fungi).
:Example: the later homonym ''
Myroxylon
''Myroxylon'' is a genus of Fabaceae native to Latin America.
History
The first described species in this genus was '' M. balsamum.'' It was originally described in 1753 by Linnaeus as ''Toluifera balsamum'', based on a specimen collected i ...
'' L.f. (1782), in the family
, is conserved against the earlier homonym ''Myroxylon'' J.R.Forst. & G.Forst. (1775) (now called ''
Xylosma
''Xylosma'' is a genus of flowering plants in the family Salicaceae. It contains around 100 species of evergreen shrubs and trees commonly known as brushhollies, xylosmas, or, more ambiguously, " logwoods". The generic name is derived from the ...
'', in the family
Salicaceae
The Salicaceae is the willow family of flowering plants. The traditional family (Salicaceae ''sensu stricto'') included the willows, poplar, aspen, and cottonwoods. Genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly ...
).
Parahomonyms
Under the botanical code, names that are similar enough that they are likely to be confused, are also considered to be homonymous (article 53.3). For example, ''Astrostemma'' Benth. (1880) is an illegitimate homonym of ''
Asterostemma'' Decne. (1838). The zoological code has a set of spelling variations (article 58) that are considered to be identical.
Hemihomonyms
Both codes only consider taxa that are in their respective scope (animals for the ICZN; primarily plants for the ICN). Therefore, if an animal taxon has the same name as a plant taxon, both names are valid. Such names are called ''hemihomonyms''. For example, the name ''Erica'' has been given to both a genus of spiders, ''
Erica
Erica or ERICA may refer to:
* Erica (given name)
* ''Erica'' (plant), a flowering plant genus
* Erica (chatbot), a service of Bank of America
* ''Erica'' (video game), a 2019 FMV video game
* ''Erica'' (spider), a jumping spider genus
* E ...
'' Peckham & Peckham, 1892, and to a genus of heaths, ''
Erica
Erica or ERICA may refer to:
* Erica (given name)
* ''Erica'' (plant), a flowering plant genus
* Erica (chatbot), a service of Bank of America
* ''Erica'' (video game), a 2019 FMV video game
* ''Erica'' (spider), a jumping spider genus
* E ...
'' L.
Hemihomonyms are possible at the species level as well, with organisms in different kingdoms sharing the same binomial. For instance, ''Orestias elegans'' denotes both a species of fish (kingdom
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
) and a species of orchid (kingdom
Plantae
Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...
). Such duplication of binomials occurs in at least eight instances.
See also
*
Glossary of scientific naming
This is a list of terms and symbols used in scientific names for organisms, and in describing the names. For proper parts of the names themselves, see List of Latin and Greek words commonly used in systematic names. Note that many of the abbreviat ...
*
Isonym
An isonym, in botanical taxonomy, is a name of a taxon that is identical to another designation, and based on the same type, but published at a different time by different authors. Citation from that source follows:
That is, the later isonyms ...
– in botany, an identical name based on the same type, but published later. Isonyms have no nomenclatural status (they are not
validly published).
References
{{reflist, 33em
Botanical nomenclature
Zoological nomenclature
01
Taxonomy (biology)