The Anatidae are the biological

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of water birds that includes

duck Duck is the common name for numerous species of waterfowl in the family (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfam ...

s, geese, and

swan Swans are birds of the genus ''Cygnus'' within the family Anatidae. The swans' closest relatives include the goose, geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe (biology) ...

s. The family has a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

, occurring on all the world's continents except Antarctica. These

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s are adapted for

swimming Swimming is the self-propulsion of a person through water, such as saltwater or freshwater environments, usually for recreation, sport, exercise, or survival. Swimmers achieve locomotion by coordinating limb and body movements to achieve hydrody ...

, floating on the water surface, and, in some cases, diving in at least shallow water. The family contains around 174 species in 43

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

(the magpie goose is no longer considered to be part of the Anatidae and is now placed in its own family, Anseranatidae). They are generally herbivorous and are monogamous breeders. A number of species undertake annual migrations. A few species have been domesticated for agriculture, and many others are hunted for food and recreation. Five species have become extinct since 1600, and many more are threatened with

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

Description and ecology

The ducks, geese, and swans are small- to large-sized birds with a broad and elongated general body plan. Diving species vary from this in being rounder. Extant species range in size from the cotton pygmy goose, at as little as 26.5 cm (10.5 in) and 164 g (5.8 oz), to the trumpeter swan, at as much as 183 cm (6 ft) and 17.2 kg (38 lb). The largest anatid ever known is the extinct flightless '' Garganornis ballmanni'' at 22 kg (49 lb). The wings are short and pointed, and supported by strong wing muscles that generate rapid beats in

flight Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...

. They typically have long necks, although this varies in degree between species. The legs are short, strong, and set far to the back of the body (more so in the more aquatic species), and have a leathery feel with a scaly texture. Combined with their body shape, this can make some species awkward on land, but they are stronger walkers than other marine and water birds such as grebes or petrels. They typically have webbed feet, though a few species such as the Nene have secondarily lost their webbing. The bills are made of soft keratin with a thin and sensitive layer of skin on top (which has a leathery feel when touched). For most species, the shape of the bill tends to be more flattened to a greater or lesser extent. These contain serrated lamellae which are particularly well defined in the filter-feeding species. Their feathers are excellent at shedding water due to special oils. Many of the ducks display

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

, with the males being more brightly coloured than the females (although the situation is reversed in species such as the paradise shelduck). The swans, geese, and whistling-ducks lack sexually dimorphic plumage. Anatids are vocal birds, producing a range of quacks, honks, squeaks, and trumpeting sounds, depending on species; the female often has a deeper voice than the male. Anatids are generally herbivorous as adults, feeding on various water-plants, although some species also eat fish, molluscs, or aquatic arthropods. One group, the mergansers, are primarily piscivorous, and have serrated bills to help them catch fish. In a number of species, the young include a high proportion of invertebrates in their diets, but become purely herbivorous as adults.

Breeding

The anatids are generally seasonal and monogamous breeders. The level of monogamy varies within the family; many of the smaller ducks only maintain the bond for a single season and find a new partner the following year, whereas the larger swans, geese and some of the more territorial ducks maintain pair bonds over a number of years, and even for life in some species. However, forced extrapair copulation among anatids is common, occurring in 55 species in 17 genera. Anatidae is a large proportion of the 3% of bird species to possess a

penis A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

, though they vary significantly in size, shape, and surface elaboration. Most species are adapted for copulation on the water only. They construct simple nests from whatever material is close at hand, often lining them with a layer of down plucked from the mother's breast. In most species, only the female incubates the eggs. The young are

precocial Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

, and are able to feed themselves from birth. One aberrant species, the black-headed duck, is an obligate brood parasite, laying its eggs in the nests of gulls and coots. While this species never raises its own young, a number of other ducks occasionally lay eggs in the nests of conspecifics (members of the same species) in addition to raising their own broods.

Relationship with humans

Duck, eider, and goose feathers and down have long been popular for bedspreads, pillows, sleeping bags, and coats. The members of this family also have long been used for food. Humans have had a long relationship with ducks, geese, and swans; they are important economically and culturally to humans, and several duck species have benefited from an association with people. However, some anatids are

agricultural Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created f ...

pests, and have acted as vectors for zoonoses such as avian influenza. Since 1600, five species of ducks have become

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

due to the activities of humans, and subfossil remains have shown that humans caused numerous extinctions in prehistory. Today, many more are considered threatened. Most of the historic and prehistoric extinctions were insular species, vulnerable due to small populations (often

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to a single island), and island tameness. Evolving on islands that lacked predators, these species lost antipredator behaviours, as well as the ability to fly, and were vulnerable to human hunting pressure and

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

. Other extinctions and declines are attributable to overhunting,

habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

and modification, and hybridisation with introduced ducks (for example the introduced ruddy duck swamping the white-headed duck in Europe). Numerous governments and conservation and hunting organisations have made considerable progress in protecting ducks and duck populations through habitat protection and creation, laws and protection, and captive-breeding programmes.

Systematics

History of classification

The name Anatidae for the

was introduced by the English zoologist

William Elford Leach William Elford Leach (2 February 1791 – 25 August 1836) was an English zoologist and marine biologist. Life and work Elford Leach was born at Hoe Gate, Plymouth, the son of an attorney. At the age of twelve he began a medical apprenticesh ...

in a guide to the contents of the

British Museum The British Museum is a Museum, public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is the largest in the world. It documents the story of human cu ...

published in 1819. While the status of the Anatidae as a family is straightforward, and which species properly belong to it is little debated, the relationships of the different tribes and subfamilies within it are poorly understood. The listing in the box at right should be regarded as simply one of several possible ways of organising the many species within the Anatidae; see discussion in the next section. The systematics of the Anatidae are in a state of flux. Previously divided into six subfamilies, a study of anatomical characters by Livezey suggests the Anatidae are better treated in nine subfamilies. This classification was popular in the late 1980s to 1990s. But mtDNA

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is cal ...

analyses indicate, for example, the dabbling and diving ducks do not belong in the same subfamily. While shortcomings certainly occur in Livezey's analysis, mtDNA is an unreliable source for phylogenetic information in many waterfowl (especially dabbling ducks) due to their ability to produce fertile hybrids, in rare cases possibly even beyond the level of genus (see for example the " Barbary duck"). Because the sample size of many molecular studies available to date is small, mtDNA results must be considered with caution. While a comprehensive review of the Anatidae which unites all evidence into a robust

phylogeny A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...

is still lacking, the reasons for the confusing data are at least clear: As demonstrated by the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

'' Vegavis iaai''—an early modern waterbird which belonged to an extinct lineage—the Anatidae are an ancient group among the modern birds. Their earliest direct ancestors, though not documented by fossils yet, likewise can be assumed to have been contemporaries with the non-avian

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s. The long period of

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

and shifts from one kind of waterbird lifestyle to another have obscured many

plesiomorph In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral Phenotypic trait, character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorph ...

ies, while apparent apomorphies are quite often the result of parallel evolution, for example the "non-diving duck" type displayed by such unrelated genera as ''

Dendrocygna The whistling ducks or tree ducks are a subfamily, Dendrocygninae, of the duck, goose and swan family of birds, Anatidae. In other Taxonomy (biology), taxonomic schemes, they are considered a separate family (biology), family, Dendrocygnidae. S ...

'', '' Amazonetta'', and '' Cairina''. For the fossil record, see below. Alternatively, the Anatidae may be considered to consist of three subfamilies (ducks, geese, and swans, essentially) which contain the groups as presented here as

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...

s, with the swans separated as subfamily Cygninae, the goose subfamily Anserinae also containing the whistling ducks, and the Anatinae containing all other

clades In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy ...

Genera

For the living and recently extinct members of each genus, see the article List of Anatidae species. * Subfamily: Dendrocygninae (one pantropical genus, of distinctive long-legged goose-like birds) ** ''

'', whistling ducks (8 living species) ** '' Thalassornis'', white-backed duck Mute swan flies arp

* Subfamily:

Anserinae The Anserinae are a subfamily in the waterfowl family Anatidae. It includes the swans and the true Goose, geese. Under alternative systematics, systematical concepts (see e.g., Terres & NAS, 1991), it is split into two subfamilies, the Anserina ...

, swans and geese (3–7 extant genera with 25–30 living species, mainly cool temperate Northern Hemisphere, but also some Southern Hemisphere species, with the

s in one genus wo genera in some treatments and the geese in three genera wo genera in some treatments Some other species are sometimes placed herein, but seem somewhat more distinct below">#Unresolved.html" ;"title="ee #Unresolved">below ** ''Swan">Cygnus'', true swans (6 species, 4 sometimes separated in ''Olor'') ** ''Anser (bird)">Anser'', grey geese and white geese (11 species) ** ''Branta'', black geese (6 living species) * Subfamily: Stictonettinae (one genus in Australia, formerly included in the Oxyurinae, but with anatomy suggesting a distinct ancient lineage perhaps closest to the Anserinae, especially the Cape Barren goose) ** '' Stictonetta'', freckled duck * Subfamily: Plectropterinae (one genus in Africa, formerly included in the "perching ducks", but closer to the Tadorninae) ** '' Plectropterus'', spur-winged goose * Subfamily:

Tadorninae The Tadornini is a biological tribe that includes the shelducks and sheldgeese, which is placed in subfamily Anatinae of family Anatinae, which includes the ducks and most duck-like waterfowl such as the geese and swans. It has been treated a ...

– shelducks and sheldgeese Common

(This group of larger, often semiterrestrial waterfowl can be seen as intermediate between Anserinae and Anatinae. The 1986 revision has resulted in the inclusion of 10 extant genera with about two-dozen living species ne probably extinctin this subfamily, mostly from the Southern Hemisphere but a few in the Northern Hemisphere; the affiliations of several presumed tadornine genera has later been questioned and the group in the traditional lineup is likely to be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

.) ** '' Tadorna'', shelducks (6 species, 1 probably

) – possibly paraphyletic ** '' Radjah'', Radjah shelduck ** '' Salvadorina'', Salvadori's teal ** '' Centrornis'', Madagascar sheldgoose (

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

, tentatively placed here) ** '' Alopochen'', Egyptian goose and Mascarene shelducks (1 living species, 2

) ** '' Neochen'', (2 species) ** '' Chloephaga'', sheldgeese (4 species) ** '' Hymenolaimus'', blue duck ** '' Merganetta'', torrent duck Male mallard duck 2

* Subfamily: Aythyinae, diving ducks (Some 15 species of diving ducks, of worldwide distribution, in two to four genera; The 1986 morphological analysis suggested the probably extinct pink-headed duck of India, previously treated separately in ''Rhodonessa'', should be placed in ''Netta'', but this has been questioned. Furthermore, while morphologically close to dabbling ducks, the mtDNA data indicate a treatment as distinct subfamily is indeed correct, with the Tadorninae being actually closer to dabbling ducks than the diving ducks) ** '' Netta'', red-crested pochard and allies (4 species, 1 probably

) ** '' Aythya'', pochards, scaups, etc. (12 species) * Subfamily:

Anatinae 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 ...

, dabbling ducks and moa-nalos (The dabbling duck group, of worldwide distribution, were previously restricted to just one or two genera, but had been extended to include eight extant genera and about 55 living species, including several genera formerly known as the "perching ducks"; mtDNA on the other hand confirms that the genus ''Anas'' is over-lumped and casts doubt on the diving duck affiliations of several genera ee below The moa-nalos, of which four species in three genera are known to date, are a peculiar group of flightless, extinct anatids from the Hawaiian Islands. Gigantic in size and with massive bills, they were believed to be geese, but have been shown to be actually very closely related to mallards. They evolved filling the

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of Resource (biology), resources an ...

of turtles, ungulates, and other megaherbivores. ** '' Anas'': pintails, mallards, etc. (40–50 living species, 3

) ** '' Chendytes'', diving-geese (extinct c. 450–250 BCE, A basal member of the dabbling duck clade) ** ''

Spatula A spatula is a broad, flat, flexible blade used to mix, spread and lift material including foods, drugs, plaster and paints. In medical applications, "spatula" may also be used synonymously with tongue depressor. The word ''spatula'' derives ...

'', shovelers ** '' Mareca'', wigeons and gadwalls ** '' Lophonetta'', crested duck ** '' Speculanas'', bronze-winged duck ** '' Amazonetta'', Brazilian teal ** '' Sibirionetta'', Baikal teal ** '' Chelychelynechen'', turtle-jawed moa-nalo (

) ** '' Thambetochen'', large-billed moa-nalos (2 species,

) ** '' Ptaiochen'', small-billed moa-nalo (

) * Tribe: Mergini, eiders, scoters, sawbills and other sea-ducks Bucephala clangula ja 01

(There are 9 extant genera and some 20 living species; most of this group occur in the Northern Hemisphere, but a few ostly extinctmergansers in the Southern Hemisphere) ** '' Shiriyanetta'' (

) ** '' Polysticta'', Steller's eider ** '' Somateria'', eiders (3 species) ** '' Histrionicus'', harlequin duck (includes ''Ocyplonessa'') ** '' Camptorhynchus'', Labrador duck (

) ** '' Melanitta'', scoters (6 species) ** '' Clangula'', long-tailed duck (1 species) ** '' Bucephala'', goldeneyes (3 species) ** '' Mergellus'', smew ** '' Lophodytes'', hooded merganser ** '' Mergus'', mergansers (4 living species, 1

). * Tribe: Oxyurini, stiff-tail ducks (a small group of 3–4 genera, 2–3 of them monotypic, with 7–8 living species) ** '' Oxyura'', stiff-tailed ducks (5 living species) ** '' Nomonyx'', masked duck ** '' Heteronetta'', black-headed duck * Unresolved: The largest degree of uncertainty concerns whether a number of genera are closer to the shelducks or to the dabbling ducks. White-winged

Prehistoric species

From subfossil bones found on Kauai ( Hawaiian Islands), two enigmatic waterfowl are known. The living and assignable prehistoric avifauna of the

archipelago An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands. An archipelago may be in an ocean, a sea, or a smaller body of water. Example archipelagos include the Aegean Islands (the o ...

contains as Anseriformes ''Branta'' geese and their descendants, and the moa-nalos as mentioned above. The following taxa, although certainly new species, cannot be assigned even to subfamily; that Kauai is the oldest of the large Hawaiian Islands, meaning the species may have been evolving in isolation for nearly 10 mya (since the Late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

), does not help in determining their affinities: * Long-legged "shelduck", Anatidae sp. et gen. indet. * Kaua'i mole duck, ''Talpanas lippa'' Similarly, '' Branta rhuax'' from the Big Island of

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

, and a gigantic goose-like anatid from

Oahu Oahu (, , sometimes written Oahu) is the third-largest and most populated island of the Hawaiian Islands and of the U.S. state of Hawaii. The state capital, Honolulu, is on Oahu's southeast coast. The island of Oahu and the uninhabited Northwe ...

are known only from very incomplete, and in the former case much damaged, bone fragments. The former has been alleged to be a shelduck, but this was generally dismissed because of the damage to the material and biogeographic considerations. The long-legged Kauai bird, however, hints at the possibility of a former tadornine presence on the archipelago.

Fossil Anatidae

The fossil record of anatids is extensive, but many prehistoric genera cannot be unequivocally assigned to present-day subfamilies for the reasons given above. For prehistoric species of extant genera, see the respective genus accounts. Dendrocheninae – a more advanced relative of the whistling-ducks or an ancestral relative of stifftail ducks paralleling whistling-ducks; if not extinct possibly belong in Oxyurinae (including '' Malacorhynchus'') * '' Mionetta'' (Late Oligocene – Middle Miocene of Central Europe and Kazakhstan) – includes ''"Anas" blanchardi'', ''"A." consobrina'', ''"A." natator'', ''"Aythya" arvernensis'' * '' Manuherikia'' (Bathans Early/Middle Miocene of Otago, New Zealand) * '' Dendrochen'' (Early – Late? Miocene) – includes ''"Anas" integra'', ''"A." oligocaena'' * Dendrocheninae gen. et sp. indet. (Late Miocene of Argentina) Black Swan skeleton

* '' Cygnavus'' (Early Miocene of Germany) * '' Cygnopterus'' (Middle Oligocene of Belgium – Early Miocene of France) – sometimes included in ''Cygnavus'' * '' Megalodytes'' (Middle Miocene of California, US) * "cf. ''Megalodytes"'' (Haraichi Middle Miocene of Annaka, Japan) * '' Anserobranta'' (Late Miocene of C Europe) – includes ''"Anas" robusta'', validity doubtful * '' Presbychen'' (Temblor Late Miocene of Sharktooth Hill, US) * '' Afrocygnus'' (Late Miocene – Early Pliocene of EC Africa) * '' Paracygnus'' (Kimball Late Pliocene of Nebraska, US) * '' Eremochen'' (Pliocene)

* '' Australotadorna'' (Late Oligocene – Early Miocene of Australia) * '' Miotadorna'' (Bathans Early/Middle Miocene of Otago, New Zealand) * Tadorninae gen. et sp. indet. (Calvert Middle Miocene of Maryland, US) * '' Balcanas'' (Early Pliocene of Dorkovo, Bulgaria) – may be synonym of ''Tadorna'' or even common shelduck * '' Anabernicula'' (Late Pliocene ? – Late Pleistocene of SW and W North America) * '' Brantadorna'' (Middle Pleistocene of Vallecito Creek, US) * '' Nannonetta'' (Late Pleistocene of Peru) * '' Zqueheanas'' (Miocene of Argentina)

* '' Sinanas'' (Middle Miocene of Shandong Province, China) * '' Wasonaka'' (Middle Pliocene of Mexico) Oxyurinae * '' Dunstanetta'' (Bathans Early/Middle Miocene of Otago, New Zealand) – tentatively placed here * '' Lavadytis'' (Miocene of Nevada, USA) * '' Pinpanetta'' (Late Oligocene – Early Miocene of Australia) * '' Tirarinetta'' (Pliocene of Australia) ''

Incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'' * '' Aldabranas'' (Late Pleistocene of Aldabra, Indian Ocean) – anatine or tadornine* ''"Anas" albae'' (Late Miocene of Polgárdi, Hungary) – mergine? Formerly in ''Mergus'' * ''"Anas" eppelsheimensis'' (Early Pliocene of Eppelsheim, Germany) – anatine? * ''"Anas" isarensis'' (Late Miocene of Aumeister, Germany) – anatine? * ''"Anas" luederitzensis'' (Kalahari Early Miocene of Lüderitzbucht, Namibia) – anatine? * ''"Anas" meyerii'' (Middle Miocene of Öhningen, Germany) Described from a single badly crushed tarsometatarsus and phalanges. This species was named in 1867 by Milne-Edwards and then recombined in 1964 by Brodkorb to the genus '' Aythya''. This species is currently regarded as Aves ''

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

''. * '' Ankonetta larriestrai'' (Miocene of Argentina) * ''"Anser" scaldii'' (Late Miocene of Antwerp, Belgium) – anserine or tadornine* Anatidae gen. et sp. indet. (Waite Late Miocene of Alcoota, Australia) – anatine, oxyurine? * ''"Anas" velox'' (Middle–Late? Miocene of C Europe) – anatine? May include ''"A." meyerii'' * Anatidae gen. et sp. indet. (Waite Late Miocene of Alcoota, Australia) – tadornine? * Anatidae gen. et sp. indet. MNZ S42797 (Bathans Early/Middle Miocene of Otago, New Zealand) * Anatidae gen. et sp. indet. (Middle Miocene of Nördlinger Ries, Germany) – tadornine? * Anatidae gen. et sp. indet. (Sajóvölgyi Middle Miocene of Mátraszõlõs, Hungary) * ''"Aythya" chauvirae'' (Middle Miocene of Sansan, France and Credinţa, Romania) – 2 species * '' Caerulonettion'' (Early Miocene of France and the Czech Republic, Middle Miocene of Germany) * '' Cayaoa'' (Early Miocene of Argentina) * ''"Chenopis" nanus'' (Pleistocene of Australia) – at least 2 taxa, may be living species * ''

Garganornis ''Garganornis'' (meaning "Gargano bird") is an extinct genus of enormous flightless anatidae, anatid waterfowl from the Late Miocene of Gargano, Italy. The genus contains one species, ''G. ballmanni'', named by Meijer in 2014. Its island gig ...

'' (Late Miocene of Gargano, Italy) * '' Gracanicanetta'' (Middle Miocene of Bosnia and Herzegovina) * '' Lavanttalornis'' (Middle Miocene of Austria) * '' Matanas'' (Bathans Early/Middle Miocene of Otago, New Zealand) * '' Mioquerquedula'' (Middle Miocene of Mongolia) * ''"Oxyura" doksana'' (Early Miocene of Dolnice, Czech Republic) * '' Protomelanitta'' (Middle Miocene of Mongolia and Nevada, USA) * '' Uyrekura'' (Early Oligocene of Kazakhstan) Putative or disputed prehistoric anatids are: * '' Romainvillia'' (Late Eocene/Early Oligocene) – anseranatid or anatid (own subfamily) * '' Loxornis'' (Deseado Early Oligocene of Argentina) * '' Paracygnopterus'' (Early Oligocene of Belgium and England) * '' Teleornis'' (Deseado Early Oligocene of Argentina) * '' Guguschia'' (Late Oligocene of Pirəkəşkül, Azerbaijan) – anserine or Pelagornithidae (same as '' Caspiodontornis''?) * '' Chenornis'' (Early Miocene) – anserine or Phalacrocoracidae * '' Paranyroca'' (Rosebud Early Miocene of Bennett County, US) – anatid (own subfamily) or distinct family? * '' Eoneornis'' (Miocene of Argentina) – anatine? A ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

'' * '' Eutelornis'' (Miocene of Argentina) – anatine? The Middle Oligocene '' Limicorallus'' (from Chelkar-Teniz (

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

) was sometimes considered an anserine. It is now recognized as a primitive cormorant. The middle Eocene '' Eonessa'' was formerly thought to belong to Anatidae, however reexamination of the holotype in 1978 resulted in the genus being placed as Aves

References

External links

Anatidae videos
on the Internet Bird Collection

– Stamps on ducks, swans and geese {{Authority control Bird families Waterfowl Extant Rupelian first appearances Taxa named by William Elford Leach