Trinomen

This article is about the naming of animals. For the naming of plants and fungi, see Infraspecific name (botany).

In zoological nomenclature, a trinomen (plural: trinomina), or trinominal name, refers to the name of a subspecies.

A trinomen is a name consisting of three names: generic name, specific name and subspecific name. The first two parts alone form the binomen or species name.

Usually, just like a binomen, the trinomen is typeset in italics, although this is not a requirement. The first letter of the trinomen (which also is the first letter of the generic name) is capitalised, and usually the rest of the name is not. No indicator of rank is included or mentioned: in zoology, subspecies is the only allowed rank below that of species.

Buteo jamaicensis borealis is one of the subspecies of the red-tailed hawk. (Buteo jamaicensis).

If the generic and specific name have already been mentioned in the same paragraph, they are often abbreviated to initial letters: for example one might write, "The Great Cormorant Phalacrocorax carbo has a distinct subspecies in Australasia, the Black Shag P. c. novaehollandiae".

In a taxonomic publication, it is customary (and recommended, but not required) that a zoological name is accompanied by an author citation, which very often will include the year of publication, and sometimes by other publication details. This indicates who published the name; and may indicate in what publication; with the date of the publication.

Phalacrocorax carbo novaehollandiae Stephens, 1826

While binomial nomenclature came into being and immediately gained widespread acceptance in the mid-18th century, it was not until the early 20th century that the current unified standard of trinominal nomenclature was agreed upon, mainly due to its tireless promotion by Elliott Coues – even though trinomina in the modern usage were pioneered in 1828 by Carl Friedrich Bruch and around 1850 widely used especially by Hermann Schlegel and John Cassin. As late as the 1930s, the use of trinomina was not fully established in all fields of zoology. Thus, when referring especially European works of the preceding era, the nomenclature used is usually not in accord with contemporary standards.

See also

• Trinomial nomenclature
• Binomial nomenclature
• Infraspecific name (botany)
• Forms in zoological literature

References

• Allen, J.A. (1884): Zoölogical [sic] Nomenclature. Auk 1(4): 338-353. PDF fulltext
• Stresemann, Ernst (1936): The Formenkreis-Theory. Auk 53(2): 150-158. PDF fulltext