A fascinating battle has gone on: Are birds really dinosaurs: Long thought to be true, a recent article says ther bones don't allow it. Birds need a certain bone structure for breathing. Also aerodynamic feathers are very complex, and there is no evidence how they arose, or when. (See Michael Denton, Evolution, A Theory in Crisis", 1986) There is also a large time gap between possible dinosaur ancestors and the appearance of birds. - http://www.eurekalert.org/pub_releases/2009-06/osu-drn060809.php