Flamingos or Flamingoes are a type of wading bird in the genus Phoenicopterus , the only genus in the family Phoenicopteridae. There are four flamingo species in the Americas and two species in the Old World.
A wide variety of birds have been proposed as their closest relatives, on a wide variety of evidence. As a result, flamingos are generally placed in their own order.
Traditionally, the long-legged Ciconiiformes, probably a paraphyletic assemblage, have been considered the flamingos' closest relatives and the family was included in the order. Usually the ibises and spoonbills of the Threskiornithidae were considered their closest relatives within this order. Earlier genetic studies, such as those of Charles Sibley and colleagues, also supported this relationship. Relationships to the waterfowl were considered as well, especially as flamingos are parasitized by feather lice of the genus Anaticola, which are otherwise exclusively found on ducks and geese. The peculiar presbyornithids were used to argue for a close relationship between flamingos, waterfowl, and waders, but they are now known to be unequivocal waterfowl.
Recent molecular studies have suggested a relation with grebes, while morphological evidence also strongly supports a relationship between flamingos and grebes. They hold at least eleven morphological traits in common, which are not found on other birds. Many of these characteristics have been previously identified on flamingos, but not on grebes. The fossil Palaelodids can be considered evolutionarily, and ecologically, intermediate between flamingos and grebes.
For the grebe-flamingo clade, the taxon Mirandornithes ("miraculous birds" due to their extreme divergence and apomorphies) has been proposed. Alternatively, they could be placed in one order, with Phoenocopteriformes taking priority.
Flamingoes are well attested in the fossil record, with the first unequivocal member of the extant family Phoenicopteridae, Elornis known from the Late Eocene. A considerable number of little-known birds from the Late Cretaceous onwards are sometimes considered to be flamingo ancestors. These include the genera Torotix, Scaniornis, Gallornis, Agnopterus, Tiliornis, Juncitarsus, and Kashinia; these show a mix of characters and are fairly plesiomorphic in comparison to modern birds. (The supposed "Cretaceous flamingo" Parascaniornis is actually a synonym of Baptornis and not a close relative to any living bird.)
An extinct family of peculiar "swimming flamingos", the Palaelodidae, are believed to be related to, or to be the ancestors of, the modern flamingos. This is sometimes rejected, since the fossil Elornis is known to be from some time before any palaelodid flamingos have been recorded. There exists a fairly comprehensive fossil record of the genus Phoenicopterus. The systematics of prehistoric Phoenicopteridae known only from fossils is as follows.