Archaeologists have discovered the fossil of a quail-sized bird that roamed the skies of southeastern China 150 million years ago, reports the journal Nature, leading archaeologists to estimate the origin of birds to be about 164 to 172 million years ago—much earlier than previously thought. This fossil has a short tail, an important aerodynamic feature that helped it fly better, much like modern-day birds. The only other such fossil from the Jurassic Period was a half-bird, half-reptile with a long tail that was found in Germany in 1862.