Taxon 199556 220821527 2008-06-21T19:24:42Z Wavelength 271168 /* See also */ adding 1 internal link: *[[Chresonym]] ([[WP:O]]) {{for|the journal|Taxon (journal)}} {{Biological classification}} A '''taxon''' (plural '''taxa'''), or '''taxonomic unit''', is a name designating an organism or a group of [[organism]]s. 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. 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 (biology)|domain]], but traditionally it was always used for animals, whereas "Division" was traditionally often used for [[plant]]s, [[fungus|fungi]], etc. A simple [[mnemonic|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 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 (biology)|Superclass]] :[[Class (biology)|Class]] :[[Subclass (biology)|Subclass]] :[[Infraclass (biology)|Infraclass]] Rank is relative, and restricted to a particular systematic schema. For example, [[liverworts]] have been grouped, in various systems of classification, as a family, order, class, or division (phylum). 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. In addition, the class rank is quite often not an evolutionary but a [[phenetic]]al 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. This has given rise to [[phylogenetic taxonomy]] and the ongoing development of the [[PhyloCode]], which is to govern the application of taxa to [[clade]]s. ==See also== *[[Alpha taxonomy]] *[[Chresonym]] *[[Cladistics]] *[[ICBN]] *[[ICZN]] *[[Rank (botany)]] *[[Rank (zoology)]] *[[Segregate (taxonomy)]] [[Category:Scientific classification]] [[Category:Zoological nomenclature]] [[Category:Botanical nomenclature]] {{Link FA|de}} [[bg:Таксон]] [[ca:Tàxon]] [[cs:Taxon]] [[cy:Tacson]] [[de:Taxon]] [[et:Takson]] [[es:Taxón]] [[eo:Taksono]] [[fa:آرایه (زیست‌شناسی)]] [[fr:Taxon]] [[hr:Takson]] [[it:Taxon]] [[he:טקסון]] [[lt:Taksonas]] [[mt:Takson]] [[nl:Taxon]] [[ja:タクソン]] [[no:Gruppe (biologi)]] [[nn:Takson]] [[nrm:Lague]] [[pl:Takson]] [[pt:Táxon]] [[ru:Таксон]] [[simple:Taxon]] [[sk:Taxón]] [[sl:Takson]] [[fi:Taksoni]] [[stq:Taxon]] [[sv:Taxon]] [[tr:Takson]] [[uk:Таксон]] [[zh:分類單元]]