Valid name (zoology) - AbsoluteAstronomy.com

Zoology

Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...

nomenclature, the valid name of a taxon

Taxon

|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

is the zoological name that is to be used for that taxon following the rules in the International Code of Zoological Nomenclature

International Code of Zoological Nomenclature

The International Code of Zoological Nomenclature is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals...

(ICZN). In other words: a valid name is the correct zoological name of a taxon.

In contrast, an invalid name is a name that violates the rules of the ICZN. An invalid name is not considered to be a correct scientific name for a taxon. Invalid names may be divided into:

Subjectively invalid names - Names that have been rendered invalid by individual scientific judgement or opinion. Taxonomists may differ in their opinion and names considered invalid by one researcher, can be accepted as valid by another; thus they are still potentially valid names. It includes:

Junior subjective synonyms - synonyms
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

described from different types previously described as separate taxa.
Junior secondary homonyms - species synonyms arising from merging two taxonomic groups previously considered separate. In this case, the taxa are separate species, but by chance, had the same specific name resulting in homonymy when their generic names
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

are synonymized.
Conditionally suppressed names - are special cases where a name which would otherwise have been valid has been petitioned for suppression by the International Commission on Zoological Nomenclatrue. This is usually because the junior synonym (the later name) has wider common usage than the senior synonym (the older name).

Objectively invalid names - Names that have been rendered invalid for factual reasons. These names are universally accepted as invalid and not merely a matter of individual opinion as is the case with subjectively invalid names. It includes:
Junior objective synonyms - names describing a taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

(the junior synonym) that have already been described by another name earlier (the senior synonym). ICZN follows the Principle of Priority
Principle of Priority
thumb|270px|Boa manditraIn zoology, the scientific study of animals, the Principle of Priority is one of the guiding principles of the International Code of Zoological Nomenclature, defined by Article 23....

, in which the oldest available name
Available name
In zoology, an available name is a scientific name for a taxon of animals that has been published conforming to all the mandatory provisions of the ICZN Code for the establishment of a zoological name....

is applied in preference to newer names where possible.
Junior homonyms in the family and genus group - names of families
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

and genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

which have the same spelling but refer to different taxa.
Junior primary homonyms in a species group - species synonyms resulting from two different organisms being originally described with the same name spelled in the same way. Compare with the previously discussed junior secondary homonyms.
Completely suppressed names - are special cases where a name is completely suppressed by the International Commission on Zoological Nomenclature. It is treated as if it had never been published and is never to be used, regardless of actual availability.
Partially suppressed names - are special cases where a name is partially suppressed by the International Commission on Zoological Nomenclature. Unlike completely suppressed names, partially suppressed names are still acknowledged as having been published but is used only for the purpose of homonymy, not priority.

See also