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.
31-422: Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae , the largest family, which includes over 170 species of waterfowl, among them the ducks , geese , and swans . Most modern species in the order are highly adapted for an aquatic existence at
62-461: 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 the field of zoology , the Linnaean orders were used more consistently. That is,
93-509: A capital letter. 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 ). 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
124-409: A considerable number of mainly Late Cretaceous and Paleogene fossils have been described where it is uncertain whether or not they are anseriforms. This is because almost all orders of aquatic birds living today either originated or underwent a major radiation during that time, making it hard to decide whether some waterbird-like bone belongs into this family or is the product of parallel evolution in
155-1182: A different lineage due to adaptive pressures. Living Anseriformes based on the work by John Boyd. Anhima [REDACTED] Chauna [REDACTED] Anseranas [REDACTED] Dendrocygna [REDACTED] Thalassornis [REDACTED] Plectropterus [REDACTED] Stictonetta Nettapus [REDACTED] Biziura [REDACTED] Heteronetta [REDACTED] Nomonyx Oxyura [REDACTED] Malacorhynchus [REDACTED] Coscoroba Cereopsis [REDACTED] Sthenelides [REDACTED] Cygnus [REDACTED] Branta [REDACTED] Anser [REDACTED] Merganetta [REDACTED] Chloephaga [REDACTED] Oressochen Neochen [REDACTED] Radjah [REDACTED] Tadorna [REDACTED] Alopochen [REDACTED] Histrionicus † Camptorhynchus [REDACTED] Clangula [REDACTED] Polysticta [REDACTED] Somateria [REDACTED] Melanitta [REDACTED] Bucephala [REDACTED] Mergellus [REDACTED] Order (biology) What does and does not belong to each order
186-570: 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 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
217-419: 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. The name of an order is usually written with
248-583: The Baikal teal , should also be considered distinct. The following genera are (with one exception) unequivocal dabbling ducks : The three known genera and four known species of moa-nalos all became extinct around AD 1000. They formerly occurred on the Hawaiian Islands and were derived from dabbling ducks, possibly even from a close ancestor of the mallard : Subfossil remains of a small, flightless dabbling duck have been recovered on Rota in
279-577: The Galliformes ( pheasants , etc.) belong to a common group, the Galloanserae . They are the most primitive neognathous birds, and as such they should follow the palaeognathae ( ratites and tinamous ) in bird classification systems. Several unusual extinct families of birds like the albatross-like pseudotooth birds and the giant flightless gastornithids and mihirungs have been found to be stem-anseriforms based on common features found in
310-707: The Hawaiian archipelago . Another bizarre insular anatine was Bambolinetta from the Late Miocene of Tuscana , then part of the Tuscano-Sardinian insular landmass. Flightless or at least a poor flyer, it instead shows adaptations for wing-propelled diving, occupying a similar ecological niche to that of penguins and plotopterids . Frequently placed into the Anatinae are these genera, whose relationships must be considered uncertain at present: On
341-528: 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 the same position. Michael Benton (2005) inserted them between superorder and magnorder instead. This position
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#1732775943044372-505: The Mariana Islands . These cannot be assigned to a known genus, but probably are closest to Anas . A most bizarre duck-like bird, Talpanas lippa has been found on the Hawaiian island of Kauai . Because of its unique apomorphies (it seems to have had small eyes high and far back on its head), the placement of this anatid is likewise unresolved; only dabbling ducks and true geese are with certainty known to have colonized
403-815: 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 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
434-506: The diving ducks , mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequence data indicates that they are fairly distant from the dabbling ducks. The morphological similarities are due to convergent evolution . In addition, the genus Anas , as traditionally defined, is not monophyletic ; several South American species belong to a distinct clade which would include the Tachyeres steamer-ducks. Other species, such as
465-475: The galliformes . These two groups only occupied two ecological niches during the Mesozoic, living in water and on the ground, while the toothed enantiornithes were the dominant birds that ruled the trees and air. The asteroid that ended the Mesozoic destroyed all trees as well as animals in the open, a condition that took centuries to recover from. The anseriformes and galliformes are thought to have survived in
496-472: The shelducks , the perching ducks , and the dabbling and diving ducks ; the latter two were presumed to make up the Anatinae. However, the perching ducks turned out to be a paraphyletic assemblage of various tropical waterfowl that happened to evolve the ability to perch well in their forested habitat . Several of these, such as the Brazilian teal , were subsequently assigned to the Anatinae. As for
527-404: The systematical status and which ducks belong to the Anatinae. Some taxonomic authorities only include the dabbling ducks and their close relatives, the extinct moa-nalos. Alternatively, the Anatinae are considered to include most " ducks ", and the dabbling ducks form a tribe Anatini within these. The classification as presented here more appropriately reflects the remaining uncertainty about
558-427: The best-known examples of sexually antagonistic genital coevolution in vertebrates, causing genital adaptations to coevolve in each sex to advance control over mating and fertilization. Sexually antagonistic coevolution (or SAC) occurs as a consequence of sexual conflict between males and females, resulting in coevolutionary process that reduce fit, or that functions to decrease ease of having sex. The Anseriformes and
589-416: The centre of their bodies. They walk well on land, and some species feed terrestrially. "Puddle ducks" generally feed on the surface of the water or feed on very shallow bottoms. They are not equipped to dive down several feet like their diving counterparts. The most prominent difference between puddle ducks and divers is the size of the feet. A puddle duck's feet are generally smaller because they do not need
620-682: The cover of burrows and water, and not to have needed trees for food and reproduction. The earliest known stem anseriform is the presbyornithid Teviornis from the Nemegt Formation of Mongolia . Some members apparently surviving the KT extinction event , including presbyornithids , thought to be the common ancestors of ducks, geese, swans, and screamers , the last group once thought to be galliformes, but now genetically confirmed to be closely related to geese. The first known duck fossils start to appear about 34 million years ago. Waterfowl are
651-529: The dabbling ducks or shelducks, is not fully resolved. See the Anatidae article for more information, and for alternate taxonomic approaches. Anatidae is traditionally divided into subfamilies Anatinae and Anserinae. The Anatinae consists of tribes Anatini , Aythyini , Mergini and Tadornini . The higher-order classification below follows a phylogenetic analysis performed by Mikko's Phylogeny Archive and John Boyd's website. Unassigned Anatidae: In addition,
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#1732775943044682-451: The dabbling ducks, is thought to be a diving duck or even a distinct subfamily. This group of ducks has been so named because its members feed mainly on vegetable matter by upending on the water surface, or grazing, and only rarely diving. These are mostly gregarious ducks of freshwater or estuaries. These birds are strong fliers and northern species are highly migratory . Compared to other types of duck, their legs are located more towards
713-423: The extra propulsion to dive for their forage. Another distinguishing characteristic of puddle ducks when compared with diving ducks is the way in which they take flight when spooked or are on the move. Puddle ducks spring straight up from the water, but diving ducks need to gain momentum to take off, so they must run across the water a short distance to gain flight. Traditionally, most ducks were assigned to either
744-423: The interrelationships of the major lineages of Anatidae (waterfowl). The dabbling duck group, of worldwide distribution, was delimited in a 1986 study to include eight genera and some 50–60 living species. However, Salvadori's teal is almost certainly closely related to the pink-eared duck , and other genera are likewise of unresolved affiliation. The peculiar marbled duck , formerly tentatively assigned to
775-708: 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
806-564: 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, 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
837-502: 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 ) 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),
868-680: The skull region, beak physiology and pelvic region. The genus Vegavis for a while was found to be the earliest member of the anseriform crown group but a recent 2017 paper has found it to be just outside the crown group in the family Vegaviidae . Below is the general consensus of the phylogeny of anseriforms and their stem relatives. † Pelagornithidae (pseudo-tooth birds) [REDACTED] † Gastornithidae [REDACTED] † Dromornithidae (mihirungs) [REDACTED] † Vegaviidae Anseriformes (screamers and waterfowl) [REDACTED] [REDACTED] [REDACTED] Anatidae systematics, especially regarding placement of some "odd" genera in
899-429: The suffix -virales . Anatini See text The Anatinae are a subfamily of the family Anatidae ( swans , geese and ducks ). Its surviving members are the dabbling ducks , which feed mainly at the surface rather than by diving . The other members of the Anatinae are the extinct moa-nalo , a young but highly apomorphic lineage derived from the dabbling ducks. There has been much debate about
930-514: The water surface. With the exception of screamers, males have penises , a trait that has been lost in the Neoaves . Due to their aquatic nature, most species are web-footed. Anseriformes are one of only two types of modern bird to be confirmed present during the Mesozoic alongside the other dinosaurs, and in fact were among the very few birds to survive their extinction, along with their cousins
961-418: 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 the ending -anae that was initiated by Armen Takhtajan 's publications from 1966 onwards. The order as