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.
17-552: Astacidea is an infraorder of decapod crustaceans including lobsters (though not "lobsters" such as the spiny lobster etc.), crayfish , and their close relatives. The Astacidea are distinguished from most other decapods by the presence of chelae (claws) on each of the first three pairs of pereiopods (walking legs), the first of which is much larger than the remaining two pairs. The last two pairs of pereiopods are simple (without claws), except in Thaumastocheles , where
34-400: A number of fossil taxa. As of 2009, the group contains 782 recognised species, over 400 of which are in the crayfish family Cambaridae . The members of the infraorder Glypheidea (containing numerous fossils and the two extant species Neoglyphea inopinata and Laurentaeglyphea neocaledonica ) were formerly included here. The cladogram below shows Astacidea's internal relationships and
51-400: A single topic. In the abstract, the resulting structures are a crucial aspect of metadata , often represented as a hierarchical structure and accompanied by descriptive information of the classes or groups. Such a classification scheme is intended to be used for the classification of individual objects into the classes or groups, and the classes or groups are based on characteristics which
68-459: 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. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may follow consistent naming schemes . Orders of plants , fungi , and algae use
85-628: The Prodromus Systematis Naturalis Regni Vegetabilis of Augustin Pyramus de Candolle and the Genera Plantarum of Bentham & Hooker, it indicated taxa that are now given the rank of family (see ordo naturalis , ' natural order '). In French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille (plural: familles )
102-407: The early split between lobsters and crayfish : Enoplometopidae Nephropidae Parastacidae Cambaroididae Astacidae Cambaridae [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] Infraorder 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
119-468: The ending -anae that was initiated by Armen Takhtajan 's publications from 1966 onwards. The order as a distinct rank of biological classification having its own distinctive name (and not just called a higher genus ( genus summum )) was first introduced by the German botanist Augustus Quirinus Rivinus in his classification of plants that appeared in a series of treatises in the 1690s. Carl Linnaeus
136-888: The field of zoology , the Linnaean orders were used more consistently. That is, the orders in the zoology part of the Systema Naturae refer to natural groups. Some of his ordinal names are still in use, e.g. Lepidoptera (moths and butterflies) and Diptera (flies, mosquitoes, midges, and gnats). In virology , the International Committee on Taxonomy of Viruses 's virus classification includes fifteen taxomomic ranks to be applied for viruses , viroids and satellite nucleic acids : realm , subrealm , kingdom , subkingdom, phylum , subphylum , class, subclass, order, suborder, family, subfamily , genus, subgenus , and species. There are currently fourteen viral orders, each ending in
153-506: The fifth pereiopod may have "a minute pincer". Members of the infraorder Astacidea are found throughout the world – both in the oceans and in fresh water – except for mainland Africa and parts of Asia. Astacidea belongs to the group Reptantia , which consists of the walking/crawling decapods (lobsters and crabs ). Astacidea is the sister clade to the infraorder Polychelida , a small group of crustaceans restricted to deep waters. The cladogram below shows Astacidea's placement within
170-837: The larger order Decapoda , from analysis by Wolfe et al. , 2019. Dendrobranchiata (prawns) [REDACTED] Stenopodidea (boxer shrimp) [REDACTED] Procarididea Caridea ("true" shrimp) [REDACTED] Achelata (spiny lobsters and slipper lobsters) [REDACTED] Polychelida (benthic crustaceans) Astacidea (lobsters and crayfish) [REDACTED] Axiidea (mud shrimp, ghost shrimp, and burrowing shrimp) Gebiidea (mud lobsters and mud shrimp) [REDACTED] Anomura (hermit crabs and allies) [REDACTED] Brachyura ("true" crabs) [REDACTED] The infraorder Astacidea comprises five extant superfamilies, two of crayfish ( Astacoidea and Parastacoidea ), one of true lobsters (Nephropoidea), one of reef lobsters (the genus Enoplometopus ), and
187-472: The objects (members) have in common. The ISO/IEC 11179 metadata registry standard uses classification schemes as a way to classify administered items, such as data elements , in a metadata registry . Some quality criteria for classification schemes are: In linguistics , subordinate concepts are described as hyponyms of their respective superordinates; typically, a hyponym is 'a kind of' its superordinate. Using one or more classification schemes for
SECTION 10
#1732868898704204-420: The same position. Michael Benton (2005) inserted them between superorder and magnorder instead. This position was adopted by Systema Naturae 2000 and others. In botany , the ranks of subclass and suborder are secondary ranks pre-defined as respectively above and below the rank of order. Any number of further ranks can be used as long as they are clearly defined. The superorder rank is commonly used, with
221-765: The suffix -ales (e.g. Dictyotales ). Orders of birds and fishes 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 ). For some clades covered by the International Code of Zoological Nomenclature , several additional classifications are sometimes used, although not all of these are officially recognized. In their 1997 classification of mammals , McKenna and Bell used two extra levels between superorder and order: grandorder and mirorder . Michael Novacek (1986) inserted them at
238-432: The suffix -virales . Classification scheme (information science) In information science and ontology , a classification scheme is an arrangement of classes or groups of classes. The activity of developing the schemes bears similarity to taxonomy , but with perhaps a more theoretical bent, as a single classification scheme can be applied over a wide semantic spectrum while taxonomies tend to be devoted to
255-574: The word family ( familia ) was assigned to the rank indicated by the French famille , while order ( ordo ) was reserved for a higher rank, for what in the 19th century had often been named a cohors (plural cohortes ). Some of the plant families still retain the names of Linnaean "natural orders" or even the names of pre-Linnaean natural groups recognized by Linnaeus as orders in his natural classification (e.g. Palmae or Labiatae ). Such names are known as descriptive family names. In
272-543: Was the first to apply it consistently to the division of all three kingdoms of nature (then minerals , plants , and animals ) in his Systema Naturae (1735, 1st. Ed.). For plants, Linnaeus' orders in the Systema Naturae and the Species Plantarum were strictly artificial, introduced to subdivide the artificial classes into more comprehensible smaller groups. When the word ordo was first consistently used for natural units of plants, in 19th-century works such as
289-540: Was used as a French equivalent for this Latin ordo . This equivalence was explicitly stated in the Alphonse Pyramus de Candolle 's Lois de la nomenclature botanique (1868), the precursor of the currently used International Code of Nomenclature for algae, fungi, and plants . In the first international Rules of botanical nomenclature from the International Botanical Congress of 1905,
#703296