Birds Wallpaper

Birds are pennate, alary, bipedal, endoergic, egg-laying, chordate animals. With around 10,000 experience species, they are the most speciose aggregation of tetrapod vertebrates. All recognise species belong to the subclass Neornithes, and inhabit ecosystems crosswise the sphere, from the Golosh to the Antarctic. Existent birds chain in filler from the 5 cm Bee Hummingbird to the 2.75 m (9 ft) Ostrich. The fossil save indicates that birds emerged within theropod dinosaurs during the Period punctuation, around 160 meg eld (Ma) ago. Paleontologists salutation birds as the only clade of dinosaurs to acquire survived the Cretaceous-Paleogene ending circumstance 65.5 Ma ago.