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).

Read more about Anseriformes:  Evolution, Systematics

Other articles related to "anseriformes":

Pelagornithidae - Taxonomy, Systematics and Evolution - Systematics and Phylogeny
... close relationship between pseudotooth birds and waterfowl (Anseriformes) ... At the side of the parasphenoid lamina, there is a wide platform as in Anseriformes ... The carpometacarpus of both Anseriformes and pseudotooth birds has a prominent pisiform process, which extends from the carpal trochlea far ...
... More recently, most consider the closest living relatives of the Gastornithiformes to be the Anseriformes (waterfowl and screamers) ... name Anserimorphae has been proposed for the Gastornithiformes and the Anseriformes, as opposed to birds closer to Galliformes ... for some 15-25 million years at least after diverging from the ancestors of the Anseriformes ...
Anseriformes - Systematics
... The Anseriformes and the Galliformes (pheasants, etc.) are the most primitive neognathous birds, and should follow ratites and tinamous in bird classification systems ... are often found to be at the base of the Anseriformes family tree, or at least their closest relatives ... Order Anseriformes †Brontornis? †Family Dromornithidae? mihirungs †Family Gastornithidae? "diatrymas" Anseres (true anseriformes) Family Anhimidae ...