Species name complex
A species name complex is an entity that describes a group of species names that share
the same etymology and grammatical behavior. For example, all species names based on the
Latin adjective palustris form the palustris species name complex.
Species name complexes are primarily useful for determining whether and how species
names need to be declined for gender, because species names that are Latin adjectives
agree in grammatical gender with the genus name. Species name complexes also make it
easier to understand the etymologies of names.
Fields
Species name complexes have the following fields:
- kind: the kind of name complex, such as an adjective or patronym. The options are
discussed more below.
- label: a unique label that identifies the complex. For complexes based on Latin
words, the label is the Latin word; for others it might be a brief description (e.g.,
non_latin).
- stem: for complexes based on Latin words, all names in the complexes end with this
stem. For example, the stem for the palustris complex is
"palustris", and the complex includes names that either are exactly palustris
(e.g., Oryzomys palustris) or palustris with some prefix (e.g.,
Sorex megapalustris).
- masculine ending: the ending the name takes in the masculine. This may be an empty
string, but if it is not, the stem will always be suffixed with this ending, because
the masculine form of an adjective is the dictionary form. For palustris, the
masculine ending is -is. Many name complexes do not change depending on gender, in
which case all three ending fields are left blank (e.g., vagrans)
- feminine ending: to find the feminine form of a name, we remove the masculine ending
from the stem, then add the feminine ending. For palustris, the feminine ending is
also -is, so the feminine and masculine forms are the same.
- neuter ending: like the feminine ending, but for the neuter form. The neuter ending
of palustris is -e, so if a palustris name is combined with a neuter genus name,
the species name becomes palustre, as with Archaeotherium palustre.
- comment: A text comment on the name complex. Often this will give an etymology.
Kinds of name complexes
Under Article 11.9.1, species names fall in one of five groups: (1) Latin adjectives,
(2) Latin nouns in the nominative case, (3) Latin or Latinized nouns in the genitive
case, (4) Latin adjectives in the genitive case, and (5) non-Latin words.
Latin adjectives
Latin and Latinized adjectives are a very common category of species names. Names in
this group are the only ones that change form depending on the grammatical gender of the
genus they are assigned to. Zoological nomenclature declines only Latin and Latinized
adjectives; adjectives in other languages, even Greek, are treated as indeclinable (Art.
31.2.3).
There are two main groups of Latin adjectives, and several smaller ones:
- First and second declension adjectives in -us, -a, -um (for example,
rufus "red").
- Third declension adjectives in -is, -is, -e (for example, agilis "agile").
This includes names in -ensis, which are commonly used with geographic
names. These adjectives are identical in the masculine and feminine forms, but the
neuter form uses the -e ending.
- Third declension adjectives in -ns, which are identical in all genders in the
nominative singular and can therefore be treated as indeclinable for the purposes of
nomenclature. This includes names like elegans "elegant" and
rufescens "reddish".
- First and second declension adjectives in -(e)r, -ra, -rum (for example,
ater "black"). These are fairly rare, but a few names in this category
are common.
- Third declension adjectives in -or, -or, -us. These are frequently comparatives,
including major "larger" and minor "smaller".
Latin has many other groups of irregular adjectives, including some that are used in
scientific names, such as alius, alia, aliud and
celer, celeris, celere.
There is a special group of names of the form adjective-i-noun, where the noun is often
a body part, like breviceps "short-headed". I believe that these names are
adjectives, although many are indeclinable.
Nouns in apposition
Latin nouns in the nominative case are fairly common as scientific names. For example,
typus "type" is common. The Code specifies (Art. 31.2.2) that names that could be
either a noun or an adjective are to be treated as nouns unless there is evidence that
the author intended them to be adjectives. This affects many names in -fer. These
names are in the "noun in apposition" complex.
Genitive nouns
Latin nouns in the genitive case are often geographic names (e.g. italiae "of Italy"),
which are included in the "genitive" complex. However, by far the most
common group are patronyms, names formed from personal names. Patronyms in turn fall
into two subgroups. Latin and Latinized names use the proper Latin genitive form, which
will frequently be a suffix of -is or -i ("patronym latin"). Modern names
are turned into patronyms by adding -i (for a man), -ae (for a
woman), -orum (for multiple men or a mixed group), or -arum (for
multiple women).
A few practical issues that arise are:
- Taxonomists regularly make mistakes with patronymic endings, like using -i when
naming a species after a group of people or using -i with a woman's name. However,
such errors may not be corrected by changing the name (see Art. 31.1.3 and 32.5).
- There is frequently variation between names in -ii and -i. The latter is the
standard non-Latin masculine patronymic ending, and the former is the result of
implicitly Latinizing a name by adding the ending -ius, then taking the genitive. In
general, the original spelling should be followed. The Code has special prohibitions
that stipulate that variation between -i and -ii is always an incorrect subsequent
spelling, not an emendation, and that -i and -ii names are homonyms even if
spelled differently (Art. 58).
Genitive adjectives
Although the Code allows for species names formed from the genitive forms of Latin
adjectives, the provision appears to be mostly intended for parasites. I have never
encountered such names in tetrapods, but the few examples in the database are included
in the "genitive adjective" complex.
Non-Latin words
A large proportion of species names are not based on Latin or Latinized words. These
names are always indeclinable. They are in the "non-Latin" complex.