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The hierarchy of biological classification's major eight taxonomic ranks. Taxonomic rank ( rank, category, taxonomic category is an abstract term used in the Scientific classification, or Taxonomy, of organisms Intermediate minor rankings are not shown.

A taxon (plural taxa), or taxonomic unit, is a name designating an organism or a group of organisms. In biological nomenclature according to Carl Linnaeus, a taxon is assigned a taxonomic rank and can be placed at a particular level in a systematic hierarchy reflecting evolutionary relationships. Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as, May 23 new style (13 May old style 1707 who laid the foundations for Taxonomic rank ( rank, category, taxonomic category is an abstract term used in the Scientific classification, or Taxonomy, of organisms

A distinction is to be made between taxa/taxonomy and classification/systematics. The former refers to biological names and the rules of naming. The latter refers to rank ordering of taxa according to presumptive evolutionary (phylogenetic) relationships.

Note: "Phylum" applies formally to any biological domain, but traditionally it was always used for animals, whereas "Division" was traditionally often used for plants, fungi, etc. In biological Taxonomy, a domain (also superregnum, superkingdom, or empire) is the highest Taxonomic rank of Organisms Plants are living Organisms belonging to the kingdom Plantae. A fungus (ˈfʌŋgəs is a eukaryotic Organism that is a member of the kingdom Fungi (ˈfʌndʒaɪ

A simple mnemonic phrase to remember the sequence of taxonomic levels is: "Dignified Kings Play Chess On Fine Green Silk"; another, highly expedient example is "King Philip's Class Orders the Family Genius to Speak". A mnemonic device (nəˈmɒnɪk is a Memory aid Commonly met mnemonics are often verbal something such as a very short poem or a special word used to help a person remember Chess is a recreational and competitive Game played between two players. Silk is a natural Protein Fiber, some forms of which can be woven into Textiles The best-known type of silk is obtained from cocoons

A prefix is used to indicate a ranking of lesser importance. The prefix super- indicates a rank above, the prefix sub- indicates a rank below. In zoology the prefix infra- indicates a rank below sub-. For instance:

Superclass

Class

Subclass

Infraclass

Rank is relative, and restricted to a particular systematic schema. A class is the Taxonomic rank in the Biological classification of organisms in Biology below phylum and above order. A class is the Taxonomic rank in the Biological classification of organisms in Biology below phylum and above order. A class is the Taxonomic rank in the Biological classification of organisms in Biology below phylum and above order. In Zoology, an infraclass is a further subdivision of a subclass, but it is rarely used For example, liverworts have been grouped, in various systems of classification, as a family, order, class, or division (phylum). The Marchantiophyta are a division of Bryophyte Plants commonly referred to as hepatics or liverworts. The use of a narrow set of ranks is challenged by users of cladistics; for example, the mere 10 ranks traditionally used between animal families (governed by the ICZN) and animal phyla (usually the highest relevant rank in taxonomic work) often cannot adequately represent the evolutionary history as more about a lineage's phylogeny becomes known. Cladistics is the hierarchical classification of Species based on evolutionary ancestry "ICZN" redirects here It is also sometimes used for the International Code of Zoological Nomenclature in error In addition, the class rank is quite often not an evolutionary but a phenetical and paraphyletic group and as opposed to those ranks governed by the ICZN, can usually not be made monophyletic by exchanging the taxa contained therein. Phenetics should not be confused with Phonetics, the study of speech sounds despite the similarity in pronunciation In Phylogenetics, a group of organisms is said to be paraphyletic if the group contains its most recent common ancestor but does not contain all This has given rise to phylogenetic taxonomy and the ongoing development of the PhyloCode, which is to govern the application of taxa to clades. Phylogenetic nomenclature (PN is an alternative to rank-based nomenclature. The International Code of Phylogenetic Nomenclature, known for short as the PhyloCode, is a developing draft for a formal set of rules governing Phylogenetic A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor

See also

• Alpha taxonomy
• Cladistics
• ICBN
• ICZN
• Rank (botany)
• Rank (zoology)
• Segregate (taxonomy)