The
genus Anas was introduced by the Swedish naturalist
Carl Linnaeus 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 phylogenetic study was published that compared
mitochondrial DNA sequences from ducks, geese and swans in the family
Anatidae. 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, ten species including the shovelers and some teals transferred to the resurrected genus
Spatula and the
Baikal teal placed in the
monotypic genus
Sibirionetta.
Species There are 31 extant species recognised in the genus: • †
Anas sp. (mid-sized species from the Late Miocene of Rudabánya, Hungary) • †
Anas bunkeri (Wetmore 1944) (Early -? Middle Pliocene – Early Pleistocene of WC USA) –
Nettion red-and-green head clade? • †
Anas ganii Burchak-Abramovich, Suspanov and David 1996 (Late Pliocene/Early Pleistocene of Moldova) • †
Anas greeni (Brodkorb 1964) (Late Miocene?/Early Pliocene of South Dakota, USA) (Late Pleistocene of Florida, USA) doubtful validity • †
Anas kisatibiensis Burchak-Abramovich and Mczedlidze 1995 (
nomen nudum) (Early Pliocene of Kisatibi,
Georgia) • †
Anas kurochkini Zelenkov & Panteleyev 2015 (Late Miocene of Sea of Azov, southern Russia) • †
Anas lambrechti Spillman 1942 [
Archaeoquerquedula lambrechti] (Pleistocene of Ecuador) • †
Anas ogallalae (Brodkorb 1962) (Late Miocene?/Early Pliocene of Kansas, USA) –
Nettion red-and-green head clade (doubtful)? •
Bermuda Islands flightless duck †
Anas pachyscelus Wetmore 1960 (Late Pleistocene of Bermuda, W Atlantic) • †
Anas pullulans (Brodkorb 1961) (Late Miocene?/Early Pliocene of Oregon, USA) –
Punanetta? • †
Anas schneideri Emslie 1985 (Late Pleistocene of Little Box Elder Cave, USA) • †
"Anas" robusta is now tentatively placed in
Anserobranta. • †
"Anas" sansaniensis is now placed in
Chenoanas • †
"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.
Anas gracilipes and
Anas strenuum (Late Pleistocene of Australia) are both junior synonyms of the extant
Chestnut teal. Highly problematic, albeit in a theoretical sense, is the placement of the
moa-nalos. These may be descended from a common ancestor of dabbling ducks such as the
Pacific black duck,
Laysan duck, and
mallard. Phylogenetically, they may even form a
clade within the traditional genus
Anas. However, when compared to these species – which are representative of dabbling ducks in general – the moa-nalos are a radical departure from the Anseriforme
bauplan. This illustrates that in a truly evolutionary sense, a strictly
phylogenetic taxonomy may be difficult to apply. ==See also==