The First Bird

Another fossil from the same area revealed new insights into how birds developed the ability to fly, according to findings in Science. The fossilized bones and feather impressions of the pigeon-sized bird dubbed Apsaravis ukhaana were uncovered in Ukhaa Tolgod in the Gobi. The creature appears to be very close to the root of the family tree of birds, which means that virtually all birds alive today may have descended from this humble beginning and that the first birds coexisted for a time with the last of the dinosaurs. The discovery rebutted the previous theory that the first birds evolved near the seashore. Previously, the fossil evidence suggested that at this time two major lines of birds existed, but that all of the species living away from the seashore died out 65 million years ago along with the dinosaurs. This latest fossil demonstrated that this ancestor bird living far from shore among the then-damp dunes of the Gobi not only outlived the dinosaurs but left descendants who proliferated into all the bird species known today. But despite its feathers and wings, an avalanche of sand caught it along with the great dinosaurs that were doomed to extinction. Perhaps this ancient bird even made a living picking insects off the hides of giant dinosaurs, just as many birds do on elephants and hippos today.

The fossilized ancestral bird found in the Gobi also provides fascinating new insights into how birds learned to fly. The sands of the Gobi preserved the buried bird so perfectly that scientists could study the way in which a muscle attached to the bone of its wing. This muscle connection in living birds helps the bird shift from an upstroke to a downstroke, which is essential in active flying instead of passive gliding. Certain versions of this bone and muscle connection appear in theropod dinosaurs, but the Gobi fossil had the more advanced refinement necessary for true, powered flight. All birds today have this muscle structure, but the Gobi fossil was the oldest example of this arrangement in any fossil. The find, possible only because of the desert’s ability to preserve even these ancient traces, pushes back the dawn of true, powered flight by anything besides insects to 80 million years. So the collision of continents, the rise of mountains, and the collapse of ancient wet dunes have yielded solutions to fundamental mysteries.