Birds- An Introduction. Early, Extinct and Extreme Birds

      Аннотация: A bird has been described as a ‘FEATHERED BIPED’. This description is apt and precise, and can apply to no other animal. Birds are warm-blooded vertebrate animals that have wings, feathers, a beak, no teeth a skeleton in which many bones are fused together or are absent, and an extremely efficient, one-way breathing system. Flying birds have strong, hollow bones and powerful flight muscles. Birds range in size from the tiny hummingbirds to the huge Ostrich and Emu. The science behind evolution, early, extinct and extreme of birds are quite interesting and imperative one.

Ключевые слова: Birds, Early, Evolution, Extinct and Early