Feathered dinosaur is possible that feathers first developed in an even earlier group, in light of the discovery of pycnofibers of pterosaurs. Crocodilians also possess beta keratin similar to those of birds, which suggests that they evolved from common ancestral genes. Shortly after the 1859 publication of Charles Darwin's "On the Origin of Species", British biologist Thomas Henry Huxley proposed that birds were descendants of dinosaurs. He compared the skeletal structure of "Compsognathus", a small theropod dinosaur, and the 'first bird' "Archaeopteryx lithographica" (both of which were found in the Upper Jurassic Bavarian limestone of Solnhofen). He showed that, apart from its
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,