In biology, a monotypic taxon is a taxonomic group with only one type. The usage differs slightly between botany and zoology:

In botany, a monotypic taxon is a taxon that has only one species: Ginkgo is a monotypic genus, while Ginkgoaceae is a monotypic family. The phrase is not accurate in cases where a species includes more than a single type; some species may include several subspecies (or other infraspecific taxa) each of which will have a type. A more accurate term in those cases is unispecific.

An example is the family Cephalotaceae, with only one species: Cephalotus follicularis, the Albany Pitcher Plant.

In zoology, a monotypic taxon is a taxon that contains only one immediately subordinate taxon.^[1] For example, a monotypic genus has only one species. Conversely, one can say that the contained taxon is monotypic within the larger taxon; a genus monotypic within a family.

An example is the genus Tarsius which is monotypic within the family Tarsiidae, which is itself monotypic in the Tarsiiformes. An example of a monotypic species is the Hyacinth Macaw (Anodorhynchus hyacinthinus), in which no subspecies can be distinguished. The Bearded Reedling (Panurus biarmicus) has numerous subspecies across its range, but belongs to the genus Panurus (monotypic as to species), which current knowledge considers monotypic within the family Panuridae.

In the view of evolutionary biology, taxonomy is a means to represent phylogenetic knowledge. Thus, it is usually avoided to establish monotypic taxa if this does not seem warranted e.g. by phylogenetic evidence such as fossils or inference from cladistic analyses^[2].

[edit] See also

• Polytypic
• Race (classification of human beings) (a more detailed definition of monotypes in the context of humans, Homo sapiens)

[edit] Footnotes

[edit] References

• Mayr E, Ashlock PD. (1991): Principles of Systematic Zoology (2nd ed.). McGraw-Hill. ISBN 0-07-041144-1
• Parham, J.F. & Feldman, C.R. (2002): Generic revisions of emydine turtles. Turtle and Tortoise Newsletter 6: 28–30. PDF fulltext