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:
“Mr. Bok is giving the bird sanctuary as a tract of land at this place. He is dedicating it as a bird sanctuary and putting up these bells to interest the birds in music.”
—Calvin Coolidge (1872–1933)
“Lord, I do fear
Thou’st made the world too beautiful this year;
My soul is all but out of me,—let fall
No burning leaf; prithee, let no bird call.”
—Edna St. Vincent Millay (1892–1950)
“The bird is not in its ounces and inches, but in its relations to Nature; and the skin or skeleton you show me, is no more a heron, than a heap of ashes or a bottle of gases into which his body has been reduced, is Dante or Washington.”
—Ralph Waldo Emerson (1803–1882)