Archaeopteryx probably cannot tell us much about the early origins of feathers and flight in true protobirds because Archaeopteryx was, in the modern sense, a bird.
Alan FeducciaOn the contrary, there is a considerable body of evidence that these fossil traces, known as 'dino-fuzz', have nothing to do with bird feathers... I, and many others, do not find any credible evidence that those structures represent protofeathers.
Alan Feduccia