Comment on Bird/Dinosaur Article

I thought this article was very interesting and logically laid out. I have always thought that birds and dinosaurs were brothers, but, after reading this article, I find myself convinced that dinosaurs and birds are quite different. As said in the article, "It's really strange that no one realized [how different they are] before."

The article explains that, for many years, birds were thought to have been the descendants of theropod dinosaurs. Recent studies and findings, however, debunk this theory. Birds have a fixed femur and walk exclusively with their knees, unlike any other animal. They have this unique bone structure so that their lungs, while flying, do not collapse under the strain that flying can cause. Dinosaurs had moveable femurs and walked using a combination of their femur and knees. Birds and dinosaurs have been linked for so long because of similarities perceived in their lung structure, but the structures surrounding dinosaur lungs and bird lungs are, in fact, entirely different. Furthermore, birds seem to appear earlier in the fossil record than dinosaurs, so birds couldn’t be descended from dinosaurs. It is more likely that birds and dinosaurs shared a common ancestor, as opposed to being directly related.