In biological classification, class (Latin: classis) is
The composition of each class is determined by a taxonomist. Often there is no exact agreement, with different taxonomists taking different positions. There are no hard rules that a taxonomist needs to follow in describing a class, but for well-known animals there is likely to be consensus. For example, dogs are usually assigned to the phylum Chordata (animals with notochords); in the class Mammalia; in the order Carnivora.
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For some clades, a number of additional classifications are used. The different classes are used relatively rarely.
Name | Meaning of prefix | Example 1 | Example 2 | Example 3[1] |
---|---|---|---|---|
Superclass | super: above | Tetrapoda | ||
Class | Mammalia | Maxillopoda | Sauropsida | |
Subclass | sub: under | Thecostraca | Avialae | |
Infraclass | infra: below | Cirripedia | Aves | |
Parvclass | parvus: small, unimportant | Neornithes |
The class as a distinct rank of biological classification having its own distinctive name (and not just called a top-level genus (genus summum) was first introduced by a French botanist Joseph Pitton de Tournefort in his classification of plants (appeared in his 1694 Eléments de botanique). Carolus Linnaeus was the first to use it consistently, in dividing of all three of his kingdoms of Nature (minerals, plants, and animals) in his Systema Naturae (1735, 1st ed.).[2] Since then class had been considered the highest level of the taxonomic hierarchy until the embranchements, now called phyla, and divisions were introduced in the nineteenth century.
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Domain/Superkingdom | Superphylum/Superdivision | Superclass | Superorder | Superfamily | Supertribe | Superspecies | ||
Kingdom | Phylum/Division | Class | Legion | Order | Family | Tribe | Genus | Species |
Subkingdom | Subphylum | Subclass | Cohort | Suborder | Subfamily | Subtribe | Subgenus | Subspecies |
Infrakingdom/Branch | Infraphylum | Infraclass | Infraorder | Section | Infraspecies | |||
Microphylum | Parvclass | Parvorder | Series | Variety | ||||
Form |