Birds and Dinosaurs

BirdNote^®

Dinosaurs Glide (or Run) to Birds

Written by Bob Sundstrom

This is BirdNote!
[Roar of a dinosaur and song of American Robin]
What is the connection, you might ask, between the blood-curdling roar of a Tyrannosaurus rex and the gentle song of a robin? A recent bonanza of fossils has intensified debate over how contemporary birds are linked to extinct dinosaurs. Today, some experts see the lineage of modern birds issuing directly from dinosaurs: that today’s birds are the surviving heirs of the dinosaurs. This is a radical departure from the long-held view that both birds and dinosaurs sprang from much earlier reptilian ancestors.
[Roar of dinosaur roar and song of American Robin]
The evidence and theories are complex. Dinosaur fossils showing feathers, hollow bones, wishbones, and flight-adapted fingers now figure in the mix. There are heated arguments over whether flight in birds developed from the “ground up” or from the “trees down.” From the “ground up,” as fast-running dinosaurs leaping into the air after prey. Or from the “trees down,” as small, ancient reptiles gliding through the forest. Or were the true ancestors of birds creatures that ran, climbed, and glided?
Don’t expect Tyrannosaurus rex in your birdbath any time soon [Roar of dinosaur roar and song of American Robin], but for a look at the fossil that’s causing all the commotion, come to our website, BirdNote.org.
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Call of the American Robin provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York.
Dinosaur sounds courtesy of YouTube.com.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2011 Tune In to Nature.org   November 2011   Narrator: Frank Corrado

ID #: 111105dinoKPLU            dinosaur-01-FCr

fossil discovery in China: http://www.dailymail.co.uk/sciencetech/article-1215998/Feathered-fossils-prove-birds-evolved-dinosaurs-say-Chinese-scientists.html