Fowl are birds belonging to one of two biological orders, namely the gamefowl or landfowl (Galliformes) and the waterfowl (Anseriformes). Anatomical and molecular similarities suggest these two groups are close evolutionary relatives; together, they form the fowl clade which is scientifically known as Galloanserae (initially termed Galloanseri) (Latin gallus (“rooster”) + ānser (“goose”)).[3] This clade is also supported by morphological and DNA sequence data[4] as well as retrotransposon presence/absence data.[5]
As opposed to "fowl", "poultry" is a term for any kind of domesticated bird or bird captive-raised for meat, eggs, or feathers; ostriches, for example, are sometimes kept as poultry, but are neither gamefowl nor waterfowl. In colloquial speech, however, the term "fowl" is often used near-synonymously with "poultry," and many languages do not distinguish between "poultry" and "fowl". Nonetheless, the fact that the Galliformes and Anseriformes most likely form a monophyletic group makes a distinction between "fowl" and "poultry" warranted.
The historic difference is due to the Germanic/Latin split word pairs characteristic of Middle English; the word 'fowl' is of Germanic origin (cf. Old English "fugol", West Frisian fûgel, Dutch vogel, German Vogel, Swedish fågel, Danish/Norwegian fugl), whilst 'poultry' is of Latin via Norman French origin.[6][7]
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.
While they are quite diverse ecologically and consequently, in an adaptation to their different lifestyles, also morphologically and ethologically, some features still unite water- and landfowl. Many of these, however, are plesiomorphic for Neornithes as a whole, and are also shared with paleognaths.[citation needed]
From the limited fossils that have to date been recovered, the conclusion that the Galloanserae were already widespread—the predominant group of modern birds—by the end of the Cretaceous is generally accepted nowadays. Fossils such as Vegavis indicate that essentially modern waterfowl, albeit belonging to a now-extinct lineage, were contemporaries of the non-avian dinosaurs. While the dominant Aviformes of the Mesozoic Era, the Enantiornithes, all died out with the dinosaurs, the Galloanserae (fowl) survived to become the first successful group of modern birds after the dinosaurs died out.