Main Page | See live article | Alphabetical index A taxon (plural taxa) is an element of a taxonomy, e.g. in the scientific classification in biology. Taxa form a hierarchical scheme, each being broken down into subtaxa. In traditional Linnaean taxonomy, taxa are ranked as follows: Kingdom Phylum (animals) or Division (plants) Class Order Family Genus Species Subspecies Variety Form The prefix super- indicates a rank above another, the prefix sub- indicates a rank below another, and the prefix infra- indicates a rank below sub-. For instance: Superclass Class Subclass Infraclass It has become generally accepted that taxa should contain an ancestral form and all or some of its descendants, though the validity of the latter category is increasingly debated. External link Rules of Biocode 1997 This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.