Archaeopteryx airfoil. This would have reduced stall speed by up to 6% and turning radius by up to 12%. The feathers of "Archaeopteryx" were asymmetrical. This has been interpreted as evidence that it was a flyer, because flightless birds tend to have symmetrical feathers. Some scientists, including Thomson and Speakman, have questioned this. They studied more than 70 families of living birds, and found that some flightless types do have a range of asymmetry in their feathers, and that the feathers of "Archaeopteryx" fall into this range. The degree of asymmetry seen in "Archaeopteryx" is more typical for slow flyers than
Specimens of Archaeopteryx suggest that it had some black colouration which included the coverts (or possibly the secondary remiges). Carney pointed out that this is consistent with what we know of modern flight characteristics, in that black melanosomes have structural properties that strengthen feathers for flight. The preservation of the fossil feather is unusual. In contrast to the feather imprints found on the full skeletons of "Archaeopteryx", the isolated feather is preserved as a dark film, which could be composed either of organic matter (as in most fossil feathers) or as inorganic minerals. Though it is theoretically possible to determine which it is,