Undescribed taxon
Encyclopedia
In taxonomy
, an undescribed taxon is a taxon
(for example, a species
) that has been discovered, but not yet formally described and named. The various Nomenclature Codes
specify the requirements for a new taxon to be validly described and named. Until such a description has been published, the taxon has no formal or official name, although a temporary, informal name is often used. A published scientific name that does not fulfil the requirements of the Codes, for example because it was not described
, is called a nomen nudum
. It is possible for a taxon to be "undescribed" for an extensive period of time, even if unofficial descriptions are published.
An undescribed species may be referred to with the genus name, followed by "sp". In some cases, there is more than one undescribed species in a genus. In this case, these are often referred to by a number or letter. In the shark genus Pristiophorus, for example, there are two undescribed species, informally named Pristiophorus sp. C and D. (In 2008, sp. A was described as Pristiophorus peroniensis and sp. B as P. delicatus.) When a formal description of one of these species is published, its temporary name will be replaced with a proper binomial name.
In bacteriology
, a valid publication of a name requires the deposition of the bacteria in a Bacteriology Culture Collection. Species for which this is impossible cannot receive a valid binomial name; these species are classified as Candidatus
.
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
, an undescribed taxon is 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...
(for example, a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
) that has been discovered, but not yet formally described and named. The various Nomenclature Codes
Nomenclature Codes
Nomenclature codes or codes of nomenclature are the various rulebooks that govern biological taxonomic nomenclature, each in their own broad field of organisms...
specify the requirements for a new taxon to be validly described and named. Until such a description has been published, the taxon has no formal or official name, although a temporary, informal name is often used. A published scientific name that does not fulfil the requirements of the Codes, for example because it was not described
Species description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...
, is called a nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
. It is possible for a taxon to be "undescribed" for an extensive period of time, even if unofficial descriptions are published.
An undescribed species may be referred to with the genus name, followed by "sp". In some cases, there is more than one undescribed species in a genus. In this case, these are often referred to by a number or letter. In the shark genus Pristiophorus, for example, there are two undescribed species, informally named Pristiophorus sp. C and D. (In 2008, sp. A was described as Pristiophorus peroniensis and sp. B as P. delicatus.) When a formal description of one of these species is published, its temporary name will be replaced with a proper binomial name.
In bacteriology
Bacteriology
Bacteriology is the study of bacteria. This subdivision of microbiology involves the identification, classification, and characterization of bacterial species...
, a valid publication of a name requires the deposition of the bacteria in a Bacteriology Culture Collection. Species for which this is impossible cannot receive a valid binomial name; these species are classified as Candidatus
Candidatus
Candidatus is in scientific classification a component of the taxonomic name for a bacterium that cannot be maintained in a Bacteriology Culture Collection. It is an interim taxonomic status for noncultivable organisms. An example would be "Candidatus Phytoplasma allocasuarinae"...
.