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Anseriformes
Whooper Swan (Cygnus cygnus), a member of the Anatidae
Whooper Swan (Cygnus cygnus), a member of the Anatidae
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Subclass: Neornithes
Infraclass: Galloanserae
Order: Anseriformes
Wagler, 1831
Families

Anhimidae
Anseranatidae
Anatidae
For fossil families, see text

The order Anseriformes contains about 150 living species of birds in three extant families: the Anhimidae (the screamers), Anseranatidae (the Magpie-goose), and the Anatidae, which includes over 140 species of waterfowl, among them the ducks, geese, and swans.

All species in the order are highly adapted for an aquatic existence at the water surface. All are web-footed for efficient swimming (although some have subsequently become mainly terrestrial).

Contents

Evolution

The earliest known Anseriform is the recently discovered Vegavis, which lived during the Cretaceous period[1]. It is thought that the Anseriformes originated when the original Galloanserae (the group to which Anseriformes and Galliformes belong) split into the two main lineages. The extinct dromornithids represent early offshoots of the anseriform line, possibly derived from screamer-like ancestors, and so maybe Gastornis (if it is an Anseriform). The ancestors of the Anseriformes developed the characteristic bill structure that they still share. The combination of the internal shape of the bill and a modified tongue acts as a suction pump to draw water in at the tip of the bill and expel it from the sides and rear; an array of fine filter plates called lamellae traps small particles, which are then licked off and swallowed.

All Anseriformes have this basic structure, but many have subsequently adopted alternative feeding strategies: geese graze on plants, the saw-billed ducks catch fish; even the screamers, which have bills that seem on first sight more like those of the game birds, still have vestigal lamellae. The prehistoric wading presbyornithids and the huge and possibly carnivorous dromornithids were even more bizarre.

Systematics

The Anseriformes and the Galliformes (pheasants etc) are the most primitive neognathous birds, and should follow ratites and tinamous in bird classification systems.

Anatidae 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.

ORDER ANSERIFORMES

Crested Screamer (Chauna torquata)
Magpie Goose (Anseranas semipalmata), sole survivng member of a Mesozoic lineage
Reconstruction of Dromornis stirtoni, a mihirung

The fossil Gastornithidae (diatrymas) are also occasionally included herein as a family.

Some fossil anseriform taxa not assignable with certainty to a family are:

In addition, 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 a different lineage due to adaptive pressures.

Footnotes

  1. ^ Clarke et al. (2005)

References

Wikibooks
Wikibooks' Dichotomous Key has more about this subject:
Anseriformes

Article is licensed under GNU Free Documentation License.
It uses material from Wikipedia.org Original article is here.



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Anseriformes - WikipediaGli Anseriformi (Anseriformes, Wagler 1831) sono un ordine della classe degli uccelli. [modifica] Alri progetti
Anseriformes - WikipediaUltima modifica per la pagina: 09:58, 8 ott 2006. Questa pagina è stata letta 15 volte. Tutti i testi sono disponibili nel rispetto dei termini della GNU Free Documentation ...
Anseriformes - Wikipedia, the free encyclopediaThe order Anseriformes contains about 150 living species of birds in three extant families: the Anhimidae (the screamers), Anseranatidae (the Magpie-goose), and the Anatidae, which ...
Anseriformes Anseridae1 Da citare come: Associazione Faunisti Veneti, 2005. (Redattori: Bon M. Sighele M. Verza E.). Rapporto ornitologico per la regione Veneto. Anno 2004.
Anseriformes - WikispeciesThis page was last modified on 31 October 2008, at 19:10. Content is available under GNU Free Documentation License. Privacy policy; About Wikispecies; Disclaimers
Category:Anseriformes - Wikimedia CommonsEnglish: The order Anseriformes contains about 150 species of bird in three families: the Anhimidae (the screamers), Anseranatidae (the Magpie-goose), and the Anatidae, which ...
Anseriformes AnseridaeBoll. Mus. civ. St. nat. Venezia, 58 (2007) 2007 269 Associazione Faunisti Veneti (Redattori: Mauro Bon, Maurizio Sighele, Emiliano Verza) RAPPORTO ORNITOLOGICO PER LAREGIONE ...
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ADW: Anseriformes: Classification What do these icons mean? The icons tell you what features are available for that taxon. Information: Pictures: Specimens: Sounds: Selecting an icon will take you directly to that ...
Anseriformes; Ducks, Geese, Swans and ScreamersAn introduction to the ecology and classification of the Anseriformes (Ducks, Geese and Swans) ... This is a medium sized order of 48 genera and 161 species divided between 4 ...

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