1. At what point did the reptilian ancestors of mammals start developing a warmblooded metabolism? 2. Birds thus did not evolve from dinosaurs but shared with them a common reptilian ancestor at a much earlier time. 3. Our own distant reptilian ancestors evolved into warm-blooded mammals, and our faces changed considerably. 4. This is the earliest bird known to paleontology to have abandoned the toothy jaws of its reptilian ancestors, replacing them with a true avian beak. 5. Some researchers who oppose the idea that birds evolved from dinosaurs embraced the new fossil as proof that birds and dinosaurs evolved independently from a common reptilian ancestor. 6. Some researchers say that if feathers developed from scales, then the new fossil is proof that birds and dinosaurs evolved independently from a common reptilian ancestor. |