This is a very quick post about something that is annoying to many biologists — the misuse of species names. It is prompted by a news headline I just saw, which is about the 10⁶th time I have seen this problem (“T. Rex”).

The binomial naming system was developed by Linnaeus in the 18th century and is still in use in modern biology. It consists of two names for each species — or, more specifically, a genus and species name. Every species should have only one genus/species name, although it takes work to correct multiple names for the same species (synonyms) and to split different species that are grouped together into a single name (cryptic species). The genus is a broader category and is (usually) comprised of many species. I will not get into the difficulty in defining what species are (though this is an interesting issue), only a few points about the use of terminology.

• The plural of “species” is “species”. The singular of “species” is also “species”, not “specie”. “Specie” refers to coins.

• The plural of “genus” is “genera”.

• Genus and species names are always written in italics.

• Genus names are capitalized, species designations are not. For example, it should be “Tyrannosaurus rex“, not “Tyrannosaurus Rex“.

• Once you have defined the species name (or if it is very well known), you can abbreviate the genus. For example, “T. rex“. The same capitalized/lowercase and italics rules apply (it does not become “T. Rex“, though watch for automated spell checkers to un-correct this for you).

• Some species are further partitioned into subspecies (although this is a more nebulous category than species); subspecies designations follow the same rules as species names (e.g., “Canis lupus familiaris“).

• Humans are categorized as Homo sapiens, the name given by Linnaeus in 1758. It means “man, the wise”. Homo sapiens is a proper noun and not a common noun, such that one human is not a “Homo sapien”.