Pteradons and the like were NOT dinosaurs. They were reptiles, but they were not actually dinosaurs.
However, that doesn't eman dinosaurs evolved into birds. For one thing, only a few species of dinosaurs probably evolved into birds, not all of them. They were probably small bipedal dinosaurs like raptors. There is evidence that rpators had feathers. These smaller feathered dinosaurs, over millions of years of natural selection would have become lighter. Their feathers would changed funtion from just insulation and display to help them to first glide, then achieve flight. There's no absolute proof that birds evolved form dinosaurs, but there's evidence in their bone structure and evidence of feathers, I'd be very surprised if birds didn't evolve from dinosaurs.
Random Manga Quote:
"You''re in love with her, but you''re too scared to deal with it...So you walk around like you got a permanet chip on your shoulder?"--Kensuke Yura. Girl Got Game volume 8 chapter 1.
