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Birds feature in the flag designs of 17 countries and numerous subnational entities and territories. [328] Birds are used by nations to symbolise a country's identity and heritage, with 91 countries officially recognising a national bird. Birds of prey are highly represented, though some nations have chosen other species of birds with parrots ...
In this diagram, the clade labelled "Neornithes" is the crown group of birds: it includes the most recent common ancestor of all living birds and its descendants, living or not. Although considered to be birds (i.e. members of the clade Aves), Archaeopteryx and other extinct groups are not included in the crown group, as they fall outside the ...
The Galliformes are a clade of bird species of cosmopolitan distribution that, with the Anseriformes, belong to the branch Galloanserae.The group have more than 270 living species and includes the megapodes, chachalacas, guans, curassows, turkeys, grouse, New World quails, pheasants, partridges and guineafowl.
The evolution of birds began in the Jurassic Period, with the earliest birds derived from a clade of theropod dinosaurs named Paraves. [1] Birds are categorized as a biological class, Aves. For more than a century, the small theropod dinosaur Archaeopteryx lithographica from the Late Jurassic period was considered to have been the earliest bird.
Passerines, the "song birds". This is the largest order of birds and contains more than half of all birds. Family Acanthisittidae. Genus Acanthisitta - rifleman; Genus Xenicus - New Zealand wrens; Family Acanthizidae - scrubwrens, thornbills, and gerygones Genus Acanthiza – thornbill; Genus Acanthornis – scrubtit; Genus Aethomyias ...
Neoaves is a clade that consists of all modern birds (Neornithes or Aves) with the exception of Palaeognathae (ratites and kin) and Galloanserae (ducks, chickens and kin). [4] This group is defined in the PhyloCode by George Sangster and colleagues in 2022 as "the most inclusive crown clade containing Passer domesticus, but not Gallus gallus". [5]
Sometimes known as perching birds, passerines generally have an anisodactyl arrangement of their toes (three pointing forward and one back), which facilitates perching. With more than 140 families and some 6,500 identified species, [ 1 ] Passeriformes is the largest order of birds and among the most diverse clades of terrestrial vertebrates ...
The crown age of a clade refers to the age of the most recent common ancestor of all of the species in the clade. The stem age of a clade refers to the time that the ancestral lineage of the clade diverged from its sister clade. A clade's stem age is either the same as or older than its crown age. [15] Ages of clades cannot be directly observed.