''Anas'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 split into four separate genera. The genus now contains 31 living species. The name ''Anas'' is the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

for "duck".

Systematics

The

''Anas'' was introduced by the Swedish naturalist

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...

in 1758 in the tenth edition of his '' Systema Naturae''. ''Anas'' is the Latin word for a duck. The genus formerly included additional species. In 2009 a large molecular phylogentic study was published that compared mitochondrial DNA sequences from ducks, geese and swans in the family

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, floating ...

. The results confirmed some of the conclusions of earlier smaller studies and indicated that the genus as then defined was non-monophyletic. Based on the results of this study, ''Anas'' was split into four proposed monophyletic genera with five species including the wigeons transferred to the resurrected genus ''

Mareca ''Mareca'' is a genus or subgenus of ducks in the family Anatidae that includes the wigeons. The species now placed in this genus were formerly placed in the genus ''Anas''. A molecular phylogentic study comparing mitochondrial DNA sequences pub ...

'', ten species including the shovelers and some teals transferred to the resurrected genus ''

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 f ...

'' and the

Baikal teal The Baikal teal (''Sibirionetta formosa''), also called the bimaculate duck or squawk duck, is a dabbling duck that breeds in eastern Russia and winters in East Asia. Taxonomy The first formal description of the Baikal teal was by the German ...

placed in the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

genus '' Sibirionetta''.

Species

There are 31 extant species recognised in the genus: Extinct Species * Mariana mallard, ''Anas oustaleti'' * Mascarene teal, ''Anas theodori'' * Chatham Island Duck, ''Anas chathamica'' Formerly placed in ''Anas'': *

Bronze-winged duck The bronze-winged duck (''Speculanas specularis'') also known as the spectacled duck, is a dabbling duck and the sole member of its genus ''Speculanas''. It is often placed in ''Anas'' with most other dabbling ducks, but its closest relative is ...

, ''Speculanas specularis'' *

Crested duck The crested duck or South American crested duck (''Lophonetta specularioides'') is a species of duck native to South America, the belonging to the monotypic genus ''Lophonetta''. It is sometimes included in ''Anas'', but it belongs to a South Am ...

, ''Lophonetta specularioides'' *

''Sibirionetta formosa'' * Salvadori's teal, ''Salvadorina waigiuensis'' *species in the genus ''

'', the wigeons (including the gadwall and the

falcated duck The falcated duck or falcated teal (''Mareca falcata'') is a gadwall-sized dabbling duck from the east Palearctic (East Siberia and Mongolia to North Japan; wintering to India). Taxonomy The closest relative of this species is the gadwall, follo ...

) *species in the genus ''

'', the shovelers and related teals

Phylogeny

Cladogram based on the analysis of Gonzalez and colleagues published in 2009.

Fossil record

Anas blanchardi aquitaniano st gerard les puys

A number of

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 preserved ...

species of ''Anas'' have been described. Their relationships are often undetermined: * †''Anas'' sp. (Late Miocene of China) * †''Anas'' sp. (mid-sized species from the Late Miocene of Rudabánya, Hungary) * †''Anas amotape'' (Campbell 1979) (Talara Tar Seeps Late Pleistocene of Peru) * †''Anas bunkeri'' (Wetmore 1944) (Early -? Middle Pliocene – Early Pleistocene of WC USA) – ''Nettion'' red-and-green head clade? * †''Anas cheuen'' Agnolín 2006 (Early-Middle Pleistocene of Argentina) – ''Dafila''? * †''Anas elapsum'' (Chinchilla Late Pleistocene of Condamine River, Australia) ("Nettion") * †''Anas ganii'' (Late Pliocene/Early Pleistocene of Tchichmiknaia, Moldavia) * †''Anas gracilipes'' (Late Pleistocene of Australia) (likely junior synonym of ''

Anas castanea The chestnut teal (''Anas castanea'') is a dabbling duck found in Australia. It is protected under the National Parks and Wildlife Act 1974. Taxonomy The chestnut teal was described by the English naturalist Thomas Campbell Eyton in 1838 unde ...

'') * †''Anas greeni'' (Brodkorb 1964) (Ash Hollow Late Miocene?/Early Pliocene of South Dakota, USA) – ''Nettion'' red-and-green head clade (doubtful)? * †''Anas itchtucknee'' McCoy 1963 * †''Anas kisatibiensis'' 'Anser kisatibiensis''(Early Pliocene of Kisatibi, Georgia) * †''Anas kurochkini'' Zelenkov & Panteleyev 2015 * †''Anas lambrechti'' 'Archaeoquerquedula lambrechti'' Stephens; ''Querquedula lambrechti''; ''Archeoquerquedula'' Spillman 1942* †''Anas ogallalae'' (Brodkorb 1962) (Ogallala Late Miocene?/Early Pliocene of Kansas, USA) – ''Nettion'' red-and-green head clade (doubtful)? * Bermuda Islands flightless duck †''Anas pachyscelus'' Wetmore 1960 (Shore Hills Late Pleistocene of Bermuda, W Atlantic) * †''Anas pullulans'' (Juntura Late Miocene?/Early Pliocene of Juntura, Malheur County,

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

, USA) – ''Punanetta''? * †''Anas schneideri'' Emslie 1985 (Late Pleistocene of Little Box Elder Cave, USA) * †''Anas sansaniensis'' Milne-Edwards 1868 'Dendrocygna sansaniensis'' (Milne-Edwards 1868) Mlíkovský 1988* †''Anas strenuum'' (Late Pleistocene of Patteramordu, Australia) ("Nettion") Several prehistoric waterfowl supposedly part of the ''Anas'' assemblage are nowadays not placed in this genus anymore, at least not with certainty: * †''"Anas" basaltica'' (Late Oligocene of "Warnsdorf", Czech Republic) is apparently an indeterminate heron. * †''"Anas" blanchardi'', ''"A." consobrina'', ''"A." natator'' are now in '' Mionetta'' * †''"Anas" creccoides'' (Early-mid Oligocene of Belgium), ''"A." risgoviensis'' (Late Miocene of Bavaria, Germany) and ''"A." skalicensis'' (Early Miocene of "Skalitz", Czech Republic), though possibly anseriform, cannot be placed with any certainty among modern birds at all. * †''"Anas" albae'' (Late Miocene of Polgárdi, Hungary), ''"A." eppelsheimensis'' (Early Pliocene of Eppelsheim, Germany), ''"A." isarensis'' (Late Miocene of Aumeister, Germany) and ''"A." luederitzensis'' (Kalahari Early Miocene of Lüderitzbucht, Namibia) are apparently

of unclear affiliations; the first might be a

seaduck The sea ducks (''Mergini'') are a tribe of the duck subfamily of birds, the Anatinae. The taxonomy of this group is incomplete. Some authorities separate the group as a subfamily, while others remove some genera. Most species within the group sp ...

. * †''"Anas" integra'' and ''"A." oligocaena'' are now in '' Dendrochen''. * †''"Anas" lignitifila'' from the Late Miocene of Tuscana has been moved to its own genus, '' Bambolinetta'', being a highly unusual marine waterfowl. * †''"Anas" robusta'' is now tentatively placed in '' Anserobranta''. * †''"Anas" velox'' (Middle – Late? Miocene of C Europe) and ''"A." meyerii'' (Middle Miocene of Öhningen, Germany; possibly the same species) do not seem to belong ''Anas'', and they may be ancestral dabbling ducks. Highly problematic, albeit in a theoretical sense, is the placement of the

moa-nalo The moa-nalo are a group of extinct aberrant, goose-like ducks that lived on the larger Hawaiian Islands, except Hawaii itself, in the Pacific. They were the major herbivores on most of these islands until they became extinct after human settle ...

s. These are in may be derived from a common ancestor of the

Pacific black duck The Pacific black duck (''Anas superciliosa''), commonly known as the PBD, is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the no ...

, the

Laysan duck The Laysan duck (''Anas laysanensis''), also known as the Laysan teal, is a dabbling duck endemic to the Hawaiian Islands. Fossil evidence reveals that Laysan ducks once lived across the entire archipelago, but today survive only on Laysan Is ...

, and the mallard, and an unknown amount of other lineages. Phylogenetically, they may even form a clade within the traditional genus ''Anas''. However, as opposed to these species – which are well representative of dabbling ducks in general – the moa-nalos are the most radical departure from the anseriform

bauplan A body plan, ( ), or ground plan is a set of morphological features common to many members of a phylum of animals. The vertebrates share one body plan, while invertebrates have many. This term, usually applied to animals, envisages a "bluep ...

known to science. This illustrates that in a truly evolutionary sense, a strictly phylogenetic taxonomy may be difficult to apply.

References

External links