Order (biology)

LifeDomainKingdomPhylumClassOrderFamilyGenusSpecies
The hierarchy of biological classification's eight major taxonomic ranks. A class contains one or more orders. Intermediate minor rankings are not shown.

Order (Latin: ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families.

What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely.[1]

The name of an order is usually written with a capital letter.[2] For some groups of organisms, their orders may follow consistent naming schemes. Orders of plants, fungi, and algae use the suffix -ales (e.g. Dictyotales).[3] Orders of birds and fishes[4] use the Latin suffix -iformes meaning 'having the form of' (e.g. Passeriformes), but orders of mammals and invertebrates are not so consistent (e.g. Artiodactyla, Actiniaria, Primates).

  1. ^ Tobin, Allan J.; Dusheck, Jennie (2005). Asking About Life. Boston: Cengage Learning. pp. 403–408. ISBN 978-0-030-27044-4.
  2. ^ Translation Bureau (2015-10-15). "Capitalization: Biological Terms". Writing Tips, TERMIUM Plus®. Public Services & Procurement Canada. Retrieved 2020-06-19.
  3. ^ McNeill et al. 2012 & Article 17.1
  4. ^ Leo S. Berg (1940). Classification of fishes, both recent and fossil (PDF) (in Russian and English). Ann Arbor Michigan: J. N. Edwards.