Nomen novum

Nomen novum (Latin for "new name"), often abbreviated as nom. nov. in scientific literature, is a term used in taxonomy to refer to a new name given to an organism when the original name is preoccupied by another species. This situation arises under the rules of the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICNafp), which govern the naming of organisms. A nomen novum is necessary when the original name of a species or genus is found to be a homonym—that is, identical in spelling to a name previously published for a different taxon in the same kingdom.

Reasons for Nomen Novum

The primary reason for the establishment of a nomen novum is to resolve the confusion created by homonyms. In biological nomenclature, each name must be unique to prevent ambiguity regarding the organism being referred to. When two taxa (the plural of taxon, a group of one or more populations of an organism or organisms seen by taxonomists to form a unit) are found to have been given the same name, one of them must be renamed to maintain nomenclatural clarity and stability.

Procedure

The procedure for establishing a nomen novum involves several steps. First, the taxonomist must demonstrate that a homonymy exists, meaning that two taxa have been assigned the same name. Next, the taxonomist selects a new name that adheres to the rules of the relevant code of nomenclature. This new name must not have been used previously within the same kingdom. Finally, the taxonomist publishes the nomen novum in a recognized scientific publication, providing a clear explanation for the change and citing the original publication where the homonym was established.

Examples

An example of a nomen novum is the renaming of the dinosaur Brontosaurus excelsus to Apatosaurus excelsus. The name Brontosaurus was found to be a junior synonym of Apatosaurus, and thus the latter name had priority according to the rules of zoological nomenclature. However, when a different species within the Brontosaurus genus was determined to be distinct enough to warrant its own genus, the name Apatosaurus could not be used, leading to the establishment of a nomen novum.

Implications

The establishment of a nomen novum has significant implications for the scientific community, particularly in the fields of taxonomy and systematics. It ensures that each species has a unique name, which is crucial for accurate communication and documentation of biological research. However, it can also lead to confusion, especially among non-specialists, when a well-known species is renamed. To mitigate this, taxonomists strive to make nomen novum changes as transparent and well-documented as possible.

See Also

• Binomial nomenclature
• Synonym (taxonomy)
• Taxonomy (biology)
• International Code of Zoological Nomenclature
• International Code of Nomenclature for algae, fungi, and plants