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 may not fulfil the requirements of the Codes for various reasons. For example, if the taxon was not adequately
described, its name 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.