In the International Code for Zoological Nomenclature (hereafter referred to as The Code), there are a number of levels a new name must pass before the validity of a name can even be considered.
The first of these levels is publication. Criteria of publication [Article 8] include things like: must be originally printed in multiple and numerous copies [Art. 8.1.3]; must be deposited in five publicly accessible libraries [Art. 8.6]; must not be handwritten, consist of photographs, audio files, or abstracts from professional meetings [Arts. 9.1, 2, 5, and 9]. These criteria are meant to insure that the name and the publication it was in (what The Code calls a 'nomenclatural act') exist in a form and in enough volume that will carry it into the future, regardless of whatever technology might persist.
The second level is called availability. Think of availability like certain privileges that are only available to names that pass the criteria. Or, another way to think about it, only names that pass the criteria are available to be used in decisions of zoological nomenclature. Names that do not pass can't, for example:
- be considered a valid name, or have priority [Art. 23.1]
- be a synonym, junior or senior [23.3]
- create coordinate family-group, genus-group, or species-group names [Arts. 36.1, 43.1, and 46.1]
- have authorship [Art. 50.1]
- be a homonym, junior or senior [Art. 52.3]
Criteria of availability include: must use the Latin alphabet [Art. 11.2]; must be in a publication that consistently applies binomial nomenclature [Art. 11.4]; must propose the name as valid when published [Art. 11.5]; must follow particular rules for the formation of names [Arts. 11.7-11.9]; must be accompanied by a diagnostic description [Art. 13.1.1] or an indication to a previously published description or other type of index [Art. 12.2]; must not be a conditional proposal of a name (if published after 1960) [Art. 15.1]; must (if published after 1999) include explicit reference to a type and type depository [Art. 16.4].
Another way to think of these criteria is as a failsafe. They enforce the creation of names in a way that is consistent with existing zoological nomeclature, and insure that the original descriptions are complete enough that other zoologists can apply the names in their own work. This is of course not true for much of the older literature. Nineteenth century taxonomy is replete with descriptions like "Small fly, body black, thorax yellow, antennae red. Location: North America", and no reference to a type. And these are available names! We can't do anything to change the availability of these old names, because the new rules of The Code are not backwards compatible. But as The Code is revised for the present era, bad taxonomy happens less often.
A historical artifact of these criteria is the nomen nudum, or 'naked name' (plural: nomina nuda). Nomen nudum, by definition, refers to any name that either fails to conform to Article 12, or 13 of The Code (depending on whether it was published before 1931 or after 1930, respectively) [Glossary, nomen nudum]. The main requirement of these two articles is an adequate, diagnostic description of the taxon. So a nomen nudum is literally a name without clothing, without substance; it's a name without a description of what it names. It may also help to think of a nomen nudum as, more generally, a name that only partially fulfills the criteria of availability.
Since nomina nuda are not available under The Code, yet fulfill some of the criteria for availability, they are in a sort of nomenclature limbo. They can be reused without changes later for the same or a different purpose, but they also might be mistakenly recognized as available. They are historical entities just as common or vernacular names, and may take the semblance of a binomial or other available name, but are not actually available. If reused, they take date and authorship from the publication that completely fulfills the criteria of availability [Art. 10.1.1]. And it's not necessary to publish that a name is a nomen nudum for it to have that status; it is unavailable by the fact it doesn't conform to the criteria, not by virtue of any later statement.
This 'nomen nudum limbo' can lead to confusion about a name's status, so the best practice is not to publicize or publish names before their formal description.
But people get excited about discovering new species. Sometimes too excited. Sometimes they are so excited they get sloppy.
In the past month there have been two instances of such careless taxonomy.
The first was a new moth named after James Cameron's film Avatar. The name was released to the press after a contest chose the species epithet ('Arctesthes avatar'), and in the discoverers' excitement they didn't consider that the press releases might be reused by print media, be archived, and contain photographs and descriptions of the species. That would meet several of the availability criteria. It is not what would traditionally be considered a nomen nudum, but it also does not conform to all the criteria. This includes Article 16, which requires explicit indication of the name as intentionally new, as well as reference to a type and the type depository.
A similar situation was that of a new species of Jamaican marine isopod published in Zootaxa this month, named Gnathia marleyi after Bob Marley. Unfortunately, the authors had published the binomial, without formal description, in a Marine Biology article in 2011! The name in the earlier publication was a nomen nudum and could be reused as is for the 2012 paper. But there was considerable confusion over the status of the earlier name, whether it was a homonym, whether it needed to be emended or not, and what the status of 'nomen nudum' actually implied.
All this trouble could have been avoided if the discoverers didn't jump the gun. Or in the latter case, the Bob Marley isopod authors could have put a statement about the nomen nudum in their 2012 paper, clarifying their mistake. (I'd also like to point out that in both cases the names were from popular culture, or as Morgan Jackson calls them, 'Celebronyms'. Do celebronyms make people do stupid things? No comment.) Editors should also do their part and be cautious about publishing names that do not yet have authorship and date; a full name citation (like Homo sapiens Linnaeus 1758) should be used the first time any binomial appears in a scientific publication. As Recommendation 10A declares, "An editor should ensure that the whole of the description and illustrations relating to a new nominal taxon, and particularly any nomenclatural acts or data necessary to confer availability on its name, are published in the same work and on the same day."
This is yet another instance where knowing and understanding The Code is so important. It's not just about getting a name published. The failsafes of publication and availability save precious time by eliminating all the homonyms and synonyms that would occur if anyone with access to a printing press could publish available names. It also saves us from wasting time publishing corrections of sloppy mistakes like the authors of the Marley isopod or the Avatar moth have made. We can instead point out their foolishness and hopefully ridicule it to the point where it doesn't happen anymore. I'm all for a future without any new nomina nuda.