The genetic markers in the DNA for growing scales are in precisely the same spot in both birds and, say, crocodiles. However, there is an extra set of genes in birds that have been shown to control the formation of feathers which crocodiles, obviously, lack. So it is obvious that feather growth is controlled differently and separately from scales. The chemical makeup of feathers is different than the chemical makeup of scales, although you can find the chemical makeup of feathers in, say, crocodilian scales, and vice versa, although not in a significant degree. These facts raise many questions.
Birds have reptilian scales.
They are chemically and genetically identical. Scutes, claw-sheathes and beaks are chemically identical to feathers. Dinosaurs also had claw-sheathes, beaks and scutes. Bird scutes being chemically identical to feathers raises the question, asked above, whether feathers could have derived from scutes. If so, the fact that dinosaurs had scutes could be further evidence for dinosaurian ancestry for birds.