Bird

Birds are feathered, winged, beaked, bipedal, endothermic (warm-blooded), egg-laying, vertebrate animals. With around 10,000 living species, they are the most speciose class of tetrapod vertebrates. Birds inhabit ecosystems across the globe, from the Arctic to the Antarctic. They emerged within theropod dinosaurs during the Jurassic period, around 150 million years ago. For more information visit the Wikipedia entry Get back to Reptile
Albatrosses & allies	† Bony-toothed birds	Cormorants & allies
Cranes & allies	Cuckoos & allies	Doves and pigeons
Eagles & allies	Extinct bird relatives	Falcons & Caracaras
Flamingos	† Gastornis & allies	Grebes
Gulls & allies	Hornbills	Hummingbirds
Kagu & allies	Kingfishers & allies	Landfowl
Loons	Nightjars & allies	Ostriches & allies
Owls	Parrots	Passerines
Pelicans & allies	Penguins	Storks
† Terror Birds	Toucans	Trogons
Turaco & allies	Waterfowl	Woodpeckers & allies