Bird
Birds (class Aves) are feathered, winged, bipedal, endothermic (warm-blooded), egg-laying, vertebrate animals. With around 10,000 living species, they are the most speciose class of tetrapod vertebrates. All present species belong to the subclass Neornithes, and inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from the 5 cm (2 in) Bee Hummingbird to the 2.75 m (9 ft) Ostrich. The fossil record indicates that birds emerged within theropod dinosaurs during the Jurassic period, around 160 million years (Ma) ago. Paleontologists regard birds as the only clade of dinosaurs to have survived the Cretaceous–Paleogene extinction event 65.5 Ma (million years) ago.
Read more about Bird.
Famous quotes containing the word bird:
“The soul has illusions as the bird has wings: it is supported by them.”
—Victor Hugo (1802–1885)
“the bird in the poplar tree
dreaming, his head
tucked into
far-and-near exile under his wing ...”
—Denise Levertov (b. 1923)
“I’ll be a new bird with the head of an ass,
Two pigs’ feet, two men’s feet, and two of a hen”
—Thomas Lovell Beddoes (1803–1849)