Anseriformes

Anseriformes Temporal range: Paleocene–Present PreꞒ Ꞓ O S D C P T J K Pg N Stem groups present since Maastrichtian[1]
Magpie goose, Anseranas semipalmata
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Clade:	Anserimorphae
Order:	Anseriformes Wagler, 1831
Extant families
Anhimidae Anseranatidae Anatidae †Dromornithidae
Range of the waterfowl and allies

Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae, the largest family, which includes over 170 species of waterfowl, among them the ducks, geese, and swans. 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. Due to their aquatic nature, most species are web-footed.