Here's a debate between a supporter of evolution and a creationist that I found online: http://www.youdebate.com/cgi-bin/scarecrow/topic.cgi?forum=3&topic=3800
It's about how birds seem to be directly linked to dinosaurs because of the discovery of an ancient bird's fossil, which seemed similar to the bone structure of a reptile.
"In fact, except for the feathers, the bird-like feet, and the fact that it had a wishbone (furcula) it didn't really look like a bird. The jaws had teeth in them, of which no bird today has. It also had the ankle bone fused to the shinbone. Clearly this bird had features of dinosaurs AND birds." --
Rob Nelson
Another theory is that if the birds did descend from the dinosaurs, it's possible that they may have dinosaur-like genes that have been simply 'switched off'. If they could somehow be turned on again, then the movie "Jurassic Park" wouldn't actually be far off from the truth...=P