Scientists discovered a fossil in China that belongs to a previously unknown species of an obscure group of small dinosaurs, related to primitive birds such as the famous Archaeopteryx. It had feathers, but they seemed too insubstantial to be useful in flight. Then the scientists said they recognized the unusually long, rod-like bone extending from each of the two wrists: curving structures possibly supporting an aerodynamic membrane. These scientists are grouping the found fossil with birds, based on structures.