Anseriformes is an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s also known as waterfowl that comprises about 180 living

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and

Anatidae The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, flo ...

, the largest family, which includes over 170 species of waterfowl, among them the

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...

s, geese, and

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

s. Most modern species in the order are highly adapted for an aquatic existence at the water surface. With the exception of screamers, males have penises, a trait that has been lost in the

Neoaves Neoaves is a clade that consists of all modern birds (Neornithes or Aves) with the exception of Paleognathae (ratites and kin) and Galloanserae (ducks, chickens and kin). Almost 95% of the roughly 10,000 known species of extant birds belong to ...

. Due to their aquatic nature, most species are web-footed.

Evolution

Anseriformes are one of only two types of modern bird to be confirmed present during the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretace ...

alongside the other dinosaurs, and in fact were among the very few birds to survive their extinction, along with their cousins the

galliformes Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are ofte ...

. 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 the cover of burrows and water, and not to have needed trees for food and reproduction. The earliest

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

anseriform found so far is '' Vegavis'', a goose-like waterfowl thought to have lived as long as 66 million years ago. 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 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.

Taxonomy

The Anseriformes and the

Galliformes Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are ofte ...

( pheasants, etc.) belong to a common group, the Galloanserae. They are the most primitive neognathous birds, and as such they should follow the

palaeognathae Palaeognathae (; ) is a infraclass of birds, called paleognaths, within the class Aves of the clade Archosauria. It is one of the two extant infraclasses of birds, the other being Neognathae, both of which form Neornithes. Palaeognathae conta ...

( ratites and

tinamou Tinamous () form an order of birds called Tinamiformes (), comprising a single family called Tinamidae (), divided into two distinct subfamilies, containing 46 species found in Mexico, Central America, and South America. The word "tinamou" co ...

s) 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 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.

Systematics

systematics, especially regarding placement of some "odd" genera in 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 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 youn ...

, Aythyini, Mergini and Tadornini. The higher-order classification below follows a

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups ...

analysis performed by Mikko's Phylogeny ArchiveMikko's Phylogeny Archiv

Paleofile.com (net, info) . and John Boyd's website.John Boyd's websit

* Order Anseriformes ** ?†'' Conflicto antarcticus, Conflicto'' Claudia P. Tambussi et al. 2019 ** †'' Naranbulagornis'' Zelenkov 2019 ** Suborder

Anhimae The screamers are three South American bird species placed in family Anhimidae. They were thought to be related to the Galliformes because of similar bills, but are more closely related to ducks (family Anatidae),Todd, F. (1991) and most close ...

Wetmore & Miller 1926 *** Genus †'' Chaunoides'' de Alvarenga 1999 *** Family Anhimidae Stejneger 1885 (screamers) **** Genus '' Anhima'' (Linnaeus 1766) Brisson 1760 (horned screamer) **** Genus '' Chauna'' Illiger 1811 ** Suborder Anseres (true Anseriformes) *** Superfamily Anseranatoidea **** Family Anseranatidae Sclater 1880 ***** Genus †'' Anserpica'' Mourer-Chauviré, Berthet & Hugueney 2004 ***** Genus †''

Eoanseranas '' Eoanseranas handae'', also sometimes referred to as Hand's dawn magpie goose, is an extinct genus and species of bird. Allied to the family Anseranatidae, which are represented by modern magpie geese, it existed during the Late Oligocene or ...

'' Worthy & Scanlon 2009 (hand's dawn magpie goose) ***** Genus †'' Anatalavis'' Olson & Parris 1987 (Late Cretaceous/Early Paleocene – Early Eocene) ***** Genus '' Anseranas'' (Latham 1798) Lesson 1828 (magpie goose) *** Superfamily Anatoidea **** Family † Presbyornithidae Wetmore 1926 (wading-"geese") ***** Genus †'' Teviornis'' Kuročkin, Dyke & Karhu 2002 ***** Genus †'' Telmabates'' Howard 1955 ***** Genus †'' Headonornis'' (Lydekker 1891) Harrison & Walker 1976 ***** Genus †''

Presbyornis ''Presbyornis'' is an extinct genus of anseriform bird. It contains two unequivocally accepted species; the well-known ''P. pervetus'' and the much lesser-known ''P. isoni''. ''P. pervetus'' was approximately the size and shape of a goose, but w ...

'' Wetmore 1926 ***** Genus †''

Wilaru ''Wilaru'' is an extinct genus of bird of uncertain phylogenetic placement from the Late Oligocene to Early Miocene of Australia. It was originally classified as a stone-curlew, but subsequently it was argued to be a member of the extinct fam ...

'' Boles et al. 2013 **** Family † Paranyrocidae Miller & Compton 1939 ***** Genus †'' Paranyroca'' Miller & Compton 1939 (Rosebud Early Miocene of Bennett County, USA) Vogels door Jan van Oort (12)

**** Family

Leach 1820 (almost 150 species) ***** Subfamily † Romainvilliinae Lambrecht 1933 ****** Genus †'' Romainvillia'' Lebedinský 1927 (Late Eocene/Early Oligocene) ****** Genus †'' Saintandrea'' Mayr & De Pietri 2013 ***** Subfamily Dendrocygninae Reichenbach 1849–50 ****** Genus '' Dendrocygna'' Swainson 1837 (whistling ducks) ****** Genus '' Thalassornis'' Eyton 1838 (white-backed duck) ***** Subfamily † Dendrocheninae Livezey & Martin 1988 ****** Genus †'' Dendrochen'' Miller 1944 ****** Genus †'' Manuherikia'' Worthy et al. 2007 ****** Genus †'' Mionetta'' Livezey & Martin 1988 ***** Subfamily Stictonettinae ****** Genus '' Stictonetta'' (Gould 1841) Reichenbach 1853 (freckled duck) ***** Subfamily

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

Vigors 1825 sensu Livezey 1996 (swans and geese) ****** Genus †'' Anserobranta'' Kuročkin & Ganya 1972 ****** Genus †'' Asiavis'' Nesov 1986 ****** Genus †'' “Chenopis”'' De Vis 1905 ****** Genus †'' Cygnavus'' Lambrecht 1931 ****** Genus †'' Cygnopterus'' Lambrecht 1931 ****** Genus †'' Eremochen'' Brodkorb 1961 ****** Genus †'' Megalodytes'' Howard 1992 ****** Genus †'' Paracygnus'' Short 1969 ****** Genus †'' Presbychen'' Wetmore 1930 ****** Genus †'' Cnemiornis'' Owen 1866 (New Zealand geese) ****** Genus †'' Afrocygnus'' Louchart et al. 2005 ****** Genus '' Coscoroba'' (Molina 1782) Reichenbach 1853 (Coscoroba swan) ****** Genus '' Cereopsis'' Latham 1801 (Cape Barren goose) ****** Genus '' Cygnus'' Garsault 1764 ****** Genus ''

Branta The black geese of the genus ''Branta'' are waterfowl belonging to the true geese and swans subfamily Anserinae. They occur in the northern coastal regions of the Palearctic and all over North America, migrating to more southernly coasts in wi ...

'' Scopoli 1769 ****** Tribe Anserini Vigors 1825 ******* Genus '' Anser'' Brisson 1760 ***** Subfamily Tadorninae Reichenbach 1849–50 (shelducks and sheldgeese) ****** Genus †'' Australotadorna'' Worthy 2009 ****** Genus †'' Brantadorna'' Howard 1964 ****** Genus †'' Centrornis'' Andrews 1897 (Malagasy sheldgoose) ****** Genus †'' Miotadorna'' Worthy et al. 2007 (St. Bathans shelduck) ****** Genus †'' Nannonetta'' Campbell 1979 ****** Genus †'' Pleistoanser'' Agnolín 2006 ****** Genus '' Plectropterus'' (Linnaeus 1766) (spur-winged goose) ****** Genus '' Merganetta'' Gould 1842 (Torrent duck) ****** Genus '' Chloephaga'' Eyton 1838 ****** Genus '' Neochen'' Oberholser 1918 ****** Genus '' Cyanochen'' (Rüppell 1845) Bonaparte 1856 (blue-winged goose) ****** Genus ''

Tadorna The shelducks, most species of which are found in the genus ''Tadorna'' (except for the Radjah shelduck, which is now found in its own monotypic genus ''Radjah''), are a group of large birds in the Tadorninae subfamily of the Anatidae, the biologi ...

'' Boie 1822 ****** Genus '' Radjah'' Reichenbach, 1853 ****** Genus ''

Alopochen ''Alopochen'' is a genus of the bird family Anatidae, part of the subfamily Tadorninae along with the shelducks. It contains one extant species, the Egyptian goose (''Alopochen aegyptiaca''), and two or three species which became extinct in ...

'' Stejneger 1885 ****** Genus ''

Cairina The Muscovy duck (''Cairina moschata'') is a large duck native to the Americas, from the Rio Grande Valley of Texas and Mexico south to Argentina and Uruguay. Small wild and feral breeding populations have established themselves in the United Sta ...

'' (Linnaeus 1758) Fleming 1822 (Muscovy duck) ****** Genus '' Hymenolaimus'' (Gmelin 1789) Gray 1843 (blue duck) ****** Genus ''

Sarkidiornis ''Sarkidiornis'' is a genus within the family ''Anatidae''. ''Sarkidiornis'' is sometimes considered a monotypic genus with its sole member the knob-billed duck (''S. melanotos''), a cosmopolitan species. Most taxonomic authorities, however, sp ...

'' Eyton 1838 ****** Genus '' Tachyeres'' Owen 1875 (steamer ducks) ***** 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 youn ...

Vigors 1825 sensu Livezey 1996 ****** Genus †'' Dunstanetta'' Worthy et al. 2007 (Johnstone's duck) ****** Genus †'' Lavadytis'' Stidham & Hilton 2015 ****** Genus †'' Pinpanetta'' Worthy 2009 ****** Genus †'' Tirarinetta'' Worthy 2008 ****** Genus ''

Aix Aix or AIX may refer to: Computing * AIX, a line of IBM computer operating systems *An Alternate Index, for a Virtual Storage Access Method Key Sequenced Data Set * Athens Internet Exchange, a European Internet exchange point Places Belgiu ...

'' Boie 1828 ****** Genus '' Callonetta'' Delacour 1936 (ringed teal) ****** Genus ''

Chenonetta ''Chenonetta'' is a genus of dabbling duck. One species is extinct, while the other is extant. Species The genus includes the following two species: * Australian wood duck (''Chenonetta jubata'') *Finsch's duck Finsch's duck (''Chenonetta f ...

'' von Brandt 1836 (Australian wood duck) ****** Genus ''

Biziura ''Biziura'' is a genus of stiff-tailed ducks endemic to Australasia and containing one living and one subfossil species. Species * †''B. delautouri'' Forbes, 1892 – New Zealand musk duck – previously endemic to New Zealand, and occurrin ...

'' Stephens 1824 (musk ducks) ****** Genus '' Pteronetta'' (Cassin 1860) Salvadori 1895 (Hartlaub's duck) ****** Genus '' Marmaronetta'' (Ménétries 1832) Reichenbach 1853 (marbled duck) ****** Genus '' Asarcornis'' (Müller 1842) Salvadori 1895 (white-winged duck) ****** Genus '' Netta'' Kaup 1829 ****** Genus '' Lophonetta'' (King 1828) Riley 1914 (crested duck) ****** Genus ''

Amazonetta The Brazilian teal or Brazilian duck (''Amazonetta brasiliensis'') is the only duck in the genus ''Amazonetta''. It is widely distributed in eastern South America. Taxonomy The Brazilian teal was formally described in 1789 by the German natu ...

'' (Gmelin 1789) von Boetticher 1929 (Brazilian teal) ****** Tribe Oxyurini Swainson 1831 (stiff-tailed ducks and allies) ****** Genus †'' Anabernicula'' Ross 1935 ******* Genus '' Heteronetta'' (Merrem 1841) Salvadori 1865 (black-headed duck) ******* Genus '' Nomonyx'' (Linnaeus 1766) Ridgway 1880 (masked duck) ******* Genus '' Oxyura'' Bonaparte 1828 ****** Genus ''

Nettapus The pygmy geese are a group of very small "perching ducks" in the genus ''Nettapus'' which breed in the Old World tropics. They are the smallest of all wildfowl. As the "perching ducks" are a paraphyletic group, they need to be placed elsewhere ...

'' von Brandt 1836 (pygmy geese) ****** Genus '' Malacorhynchus'' Swainson 1831 (pink-eared duck) ****** Genus '' Salvadorina'' Rothschild & Hartert 1894 (Salvadori's teal) ****** Genus '' Speculanas'' (King 1828) von Boetticher 1929 (bronze-winged duck) ****** Tribe Mergini Rafinesque 1815 (eiders, scoters, mergansers and other sea-ducks) ******* Genus †''

Chendytes ''Chendytes lawi'' is an extinct, goose-sized flightless marine duck, once common on the California coast, the California Channel Islands, and possibly southern Oregon. It lived in the Pleistocene and survived into the Holocene. It appears ...

'' Miller 1925 ******* Genus †'' Shiriyanetta'' Watanabe & Matsuoka 2015 ******* Genus †''

Camptorhynchus The Labrador duck (''Camptorhynchus labradorius'') was a North American bird; it has the distinction of being the first known endemic North American bird species to become extinct after the Columbian Exchange, with the last known sighting occurr ...

'' (Gmelin 1789) Bonaparte 1838 (Labrador duck) ******* Genus ''

Histrionicus The harlequin duck (''Histrionicus histrionicus'') is a small sea duck. It takes its name from Harlequin (French ''Arlequin'', Italian ''Arlecchino''), a colourfully dressed character in Commedia dell'arte. The species name comes from the Latin ...

'' Lesson 1828 (harlequin duck) ******* Genus ''

Clangula The long-tailed duck (''Clangula hyemalis''), formerly known as oldsquaw, is a medium-sized sea duck that breeds in the tundra and taiga regions of the arctic and winters along the northern coastlines of the Atlantic and Pacific Oceans. It is th ...

'' Leach 1819 (long-tailed duck) ******* Genus '' Polysticta stelleri'' (Pallas 1769) Eyton 1836 (Steller's eider) ******* Genus '' Somateria'' Leach 1819 (eiders) ******* Genus '' Melanitta'' Boie 1822 (scoters) ******* Genus '' Bucephala'' Baird 1858 ******* Genus ''

Mergellus ''Mergellus'' is a genus of duck. The smew ''(Mergellus albellus)'' is the only living species, but an extinct species known as '' Mergellus mochanovi'' has also been described from Late Pleistocene deposits in the Yakutia Sakha, officially ...

'' Selby 1840 (Smew) ******* Genus '' Lophodytes'' (Linnaeus 1758) Reichenbach 1853 (hooded merganser) ******* Genus '' Mergus'' Linnaeus 1758 non Brisson 1760 ****** Tribe

Vigors 1825 sensu Livezey 1996 (dabbling ducks and moa-nalos) ******* Genus †'' Matanas'' Worthy et al. 2007 (Enright's duck) ******* Genus ''

Anas ''Anas'' is a genus of dabbling ducks. It includes the pintails, most teals, and the mallard and its close relatives. It formerly included additional species but following the publication of a molecular phylogenetic study in 2009 the genus was s ...

'' Linnaeus 1758 ******* Genus '' Sibirionetta'' (Georgi 1775) (Baikal teal) ******* Genus '' Mareca'' (Stephens 1824) ******* Genus '' Spatula'' Boie 1822 ****** Tribe Aythyini Delacour and Mayr, 1945 (diving ducks) ******* Genus '' Aythya'' Boie 1822 Some fossil anseriform taxa not assignable with certainty to a family are: * †'' Proherodius'' (London Clay Early Eocene of London, England) – Presbyornithidae? * †''

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

'' Meijer 2014 Unassigned Anatidae: * †'' "Anas" albae'' Jánossy 1979 ''Mergus''* †'' "Anas" amotape'' Campbell 1979 * †'' "Anas" isarensis'' Lambrecht 1933 * †'' "Anas" luederitzensis'' * †'' "Anas" sanctaehelenae'' Campbell 1979 * †'' "Anas" eppelsheimensis'' Lambrecht 1933 * †'' "Oxyura" doksana'' Mlíkovský 2002 * †'' "Anser" scaldii'' Anas" scaldii* †'' Ankonetta larriestrai'' Cenizo & Agnolín 2010 * †'' Cayaoa bruneti'' Tonni 1979 * †'' Eoneornis'' nomen dubium * †'' Eutelornis'' * †'' Aldabranas cabri'' Harrison & Walker 1978 * †'' Chenoanas deserta'' Zelenkov 2012 * †'' Cygnopterus alphonsi'' Cheneval 1984 on_''Cygnavus_senckenbergi''_Mlíkovský_2002.html" ;"title="Cygnavus_senckenbergi.html" ;"title="on '' on_''Cygnavus_senckenbergi''_Mlíkovský_2002">Cygnavus_senckenbergi.html"_;"title="on_''Cygnavus_senckenbergi">on_''Cygnavus_senckenbergi''_Mlíkovský_2002*_†'' on_''Cygnavus_senckenbergi''_Mlíkovský_2002">Cygnavus_senckenbergi.html"_;"title="on_''Cygnavus_senckenbergi">on_''Cygnavus_senckenbergi''_Mlíkovský_2002*_†''Helonetta">Helonetta_brodkorbi''_Emslie_1992 *_†'' on_''Cygnavus_senckenbergi''_Mlíkovský_2002">Cygnavus_senckenbergi.html"_;"title="on_''Cygnavus_senckenbergi">on_''Cygnavus_senckenbergi''_Mlíkovský_2002*_†''Helonetta">Helonetta_brodkorbi''_Emslie_1992 *_†''Loxornis">Loxornis_clivus''_Ameghino_1894 *_†''Mioquerquedula.html" ;"title="Loxornis.html" ;"title="Helonetta.html" ;"title="Cygnavus senckenbergi">on ''Cygnavus senckenbergi'' Mlíkovský 2002">Cygnavus_senckenbergi.html" ;"title="on ''Cygnavus senckenbergi">on ''Cygnavus senckenbergi'' Mlíkovský 2002* †''Helonetta">Helonetta brodkorbi'' Emslie 1992 * †''Loxornis">Loxornis clivus'' Ameghino 1894 * †''Mioquerquedula">Mioquerquedula minutissima'' Zelenkov & Kuročkin 2012 [''Anas velox'' Milne-Edwards 1867] * †''Paracygnopterus, Paracygnopterus scotti'' Harrison & Walker 1979 * †''Proanser, Proanser major'' Umanskaya 1979 * †'' Teleornis'' Ameghino 1899 * †'' Protomelanitta'' Zelenkov 2011 * †'' Nogusunna conflictoides'' Zelenkov 2011 * †'' Sharganetta mongolica'' Zelenkov 2011 * '' Metopiana'' Bonaparte 1856 'Metopias''_Heine_&_Reichenow_1890;_''Phoeonetta.html" ;"title="Metopias.html" ;"title="'Metopias">'Metopias'' Heine & Reichenow 1890; ''Phoeonetta">Metopias.html" ;"title="'Metopias">'Metopias'' Heine & Reichenow 1890; ''Phoeonetta'' Delacour 1937; ''Netta (Phoeoaythia)'' Delacour 1937] * †''Bambolinetta'' (Portis 1884) Mayr & Pavia 2014 [''Anas lignitifila'' Portis 1884] * †''Heteroanser, Heteroanser vicinus'' (Kuročkin 1976) Zelenkov 2012 'Heterochen_vicinus''_Kuročkin_1976;_''Anser_vicinus.html" ;"title="Heterochen_vicinus.html" ;"title="'Heterochen vicinus">'Heterochen vicinus'' Kuročkin 1976; ''Anser vicinus">Heterochen_vicinus.html" ;"title="'Heterochen vicinus">'Heterochen vicinus'' Kuročkin 1976; ''Anser vicinus'' (Kuročkin 1976) Mlíkovský & Švec 1986] * †''Sinanas'' Yeh 1980 * †''Talpanas'' Olson & James 2009 (Kaua'i mole duck) * †''Wasonaka'' Howard 1966 * †''Chelychelynechen'' Olson & James 1991 (turtle-jawed moa-nalo) * †'' Ptaiochen'' Olson & James 1991 (small-billed moa-nalo) * †'' Thambetochen'' Olson & Wetmore 1976 In addition, a considerable number of mainly Late Cretaceous and

Paleogene The Paleogene ( ; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( Mya) to the beginning o ...

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 In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

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 a different lineage due to adaptive pressures. * "Presbyornithidae" gen. et sp. indet. (Barun Goyot Late Cretaceous of Udan Sayr, Mongolia) – Presbyornithidae? * UCMP 117599 (Hell Creek Late Cretaceous of Bug Creek West, USA) * '' Petropluvialis'' (Late Eocene of England) – may be same as ''Palaeopapia'' * '' Agnopterus'' (Late Eocene – Late Oligocene of Europe) – includes ''Cygnopterus lambrechti'' * ''"Headonornis hantoniensis"'' BMNH PAL 4989 (Hampstead Early Oligocene of Isle of Wight, England) – formerly ''"Ptenornis"'' * '' Palaeopapia'' (Hampstead Early Oligocene of Isle of Wight, England) * ''"Anas" creccoides'' (Early/Middle Oligocene of Belgium) * ''"Anas" skalicensis'' (Early Miocene of "Skalitz", Czech Republic) * ''"Anas" risgoviensis'' (Late Miocene of Bavaria, Germany) * †'' "Anas" meyerii'' Milne-Edwards 1867 'Aythya_meyerii''_(Milne-Edwards_1867)_Brodkorb_1964.html" ;"title="Aythya_meyerii.html" ;"title="' 'Aythya_meyerii''_(Milne-Edwards_1867)_Brodkorb_1964">Aythya_meyerii.html"_;"title="'Aythya_meyerii">'Aythya_meyerii''_(Milne-Edwards_1867)_Brodkorb_1964*_†'' 'Aythya_meyerii''_(Milne-Edwards_1867)_Brodkorb_1964">Aythya_meyerii.html"_;"title="'Aythya_meyerii">'Aythya_meyerii''_(Milne-Edwards_1867)_Brodkorb_1964*_†''Eonessa">Eonessa_anaticula''_Wetmore_1938_

_Phylogeny

Living_Anseriformes_based_on_the_work_by_John_Boyd. Image:Zoo_América-2897-Chauna_torquata.jpg.html" ;"title="Eonessa.html" ;"title="Aythya meyerii">' Aythya_meyerii.html"_;"title="'Aythya_meyerii">'Aythya_meyerii''_(Milne-Edwards_1867)_Brodkorb_1964*_†''Eonessa">Eonessa_anaticula''_Wetmore_1938_

_Phylogeny

Living_Anseriformes_based_on_the_work_by_John_Boyd. Image:Zoo_América-2897-Chauna_torquata.jpg">Crested_screamer_(''Chauna_torquata'') Image:magpie.goose.grooming.arp.750pix.jpg.html" ;"title="Aythya meyerii'' (Milne-Edwards 1867) Brodkorb 1964">Aythya_meyerii.html" ;"title="' 'Aythya_meyerii''_(Milne-Edwards_1867)_Brodkorb_1964*_†''Eonessa">Eonessa_anaticula''_Wetmore_1938_

_Phylogeny

Living_Anseriformes_based_on_the_work_by_John_Boyd. Image:Zoo_América-2897-Chauna_torquata.jpg">Crested_screamer_(''Chauna_torquata'') Image:magpie.goose.grooming.arp.750pix.jpg">Magpie_goose_(''Anseranas_semipalmata''),_sole_surviving_member_of_a_Mesozoic_ The_Mesozoic_Era_(_),_also_called_the_Age_of_Reptiles,_the_Age_of_Conifers,_and_colloquially_as_the_Age_of_the_Dinosaurs_is_the_second-to-last__era_of_Earth's__geological_history,_lasting_from_about_,_comprising_the_Triassic,_Jurassic_and_Cretace_...

Evolution

Taxonomy

Systematics

_Phylogeny

_Phylogeny

_Phylogeny

Phylogeny

Molecular studies

See also

References

Cited texts