A group of American and German paleontologists have studied a fossil feather of Archaeopteryx, considered for years the first bird in the world. Researchers have compared the structures to store the pigment of this pen with the current bird feathers. And both in size and shape closely resemble the structures of Archaeopteryx and the blackest today. Therefore, researchers have concluded that the Archaeopteryx pen was almost certain. However, to know if the whole bird was black, researchers have stated that it would be necessary to clarify whether the feather was outside the bird, as well as find other fossilized feathers.