Galloanserans
Chickens are a well-known member of this ancient clade
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Subclass: Neornithes Infraclass: Neognathae Superorder: Galloanserae Sibley, Ahlquist & Monroe, 1988
Orders
Galliformes Anseriformes

The birds referred to as fowl belong to one of two orders, namely the gamefowl or landfowl (Galliformes) and the waterfowl (Anseriformes). Interestingly, studies of anatomical and molecular similarities suggest these two groups were close evolutionary relatives; together, they form the fowl clade which is scientifically known as Galloanserae. This clade has been supported by Retrotransposon presence/absence data as well.

"Poultry", on the other hand, is a term for any kind of domesticated bird or bird captive-raised for meat or eggs; ostriches for example are sometimes kept as poultry, but are neither gamefowl nor waterfowl. In colloquial speech, the term "fowl" is however often used near-synonymously with "poultry" or even "bird", and many languages do not distinguish between "poultry" and "fowl". Nonetheless, the fact that Galliformes and Anseriformes most likely form a monophyletic group makes a distinction between "fowl" and "poultry" warranted.

Many birds that are eaten by humans are fowl, including poultry such as chickens or turkeys, game birds such as pheasants or partridges, other wildfowl like guineafowl or peafowl, and waterfowl such as ducks or geese.

Fowl were the first neognathe lineages to evolve. From the limited fossils that have to date been recovered, the conclusion that they were already widespread - indeed the predominant group of modern birds - by end of the Cretaceous is generally accepted nowadays. Fossils such as Vegavis indicate that essentially modern waterfowl - albeit belonging to a nowadays extinct lineage - were contemporaries of the (non-avian) dinosaurs. As opposed to the morphologically fairly conservative Galliformes, the Anseriformes have adapted to filter-feeding and are characterized by a large number of autapomorphies related to this lifestyle. The extremely advanced feeding systems of the Anseriformes, together with similarities of the early anseriform Presbyornis to shorebirds, had formerly prompted some scientists to ally Anseriformes with Charadriiformes instead (see also "Graculavidae"). However, strong support for the Galloanserae has emerged in more recent studies based on new molecular and morphological analyses; the fowl clade continues to be accepted as a genuine evolutionary lineage by the vast majority of scientists.

See also

• Critique of Galloanseres monophyly at EvoWiki.

References

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Source: adapted by the editor from Wikipedia, the free encyclopedia; from the article "Fowl". Image Credit.

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