Birds' Oldest Ancestor Lived 130 Million Years Ago

The oldest known relative of all birds alive today has just been unearthed in northeastern China.

The ultimate early bird, Archaeornithura meemannae, lived 130.7 million years ago -- pushing back the evolutionary record of modern birds by around 6 million years.

At 145 million years old, Archaeopteryx is still the oldest and most primitive known bird, but it has no living descendants. A. meemannae, on the other hand, has been placed in the clade Ornithuromorpha, which is the same evolutionary branch that gave rise to all bird species currently living. It's described in the latest issue of the journal Nature Communications.

The newly found bird looked "nearly" like today's shorebirds, senior author Zhonghe Zhou told Discovery News, although A. meemannae "could have been preyed upon by carnivorous dinosaurs."

Zhou is director of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences. He and his colleagues analyzed the remains of the bird, represented by two very well-preserved specimens.

"Its forelimbs were shorter than its hind limbs, which is quite unusual," lead author Min Wang said.

Because of its long legs and other anatomy, the researchers think the ancient bird spent much of its time near the shores of a lake, patrolling the area looking for insects and other small prey to eat. To this day, long-legged birds like cranes and herons have a somewhat similar lifestyle.

It sported feathers and was capable of flight, yet its wings were short, so the scientists think the bird had a mostly terrestrial existence.

Feathered dinosaurs lived during the Jurassic and Cretaceous Periods in China, with only some evolving to become birds like A. meemannae. Scientists haven't pinpointed which dinosaurs are the direct ancestors to birds, but possible candidates are dromaeosaurids, troodontids and scansoriopterygids, Wang and Zhou said.

Such dinosaurs "probably lived in a forest environment," according to Zhou, and were "climbing, jumping and gliding." These feats were possible, in part, since the dinosaurs had feathered or bat-like wings.

The dinosaurs that did evolve into birds first gave rise to Archaeopteryx, as well as another ancient bird called Jeholornis, and more, the scientists said. A further stage of evolution resulted in A. meemannae and its relatives.

Non-avian (meaning not-bird) dinosaurs died out during a mass extinction event that occurred 65 million years ago. Some birds, such as a bizarre group that had teeth and clawed wings, bit the dust then too.

As for why other birds, including some relatives of A. meemannae, survived, Zhou said, "These birds had a lot of advantages...better flight, and more modern physiology, and they could escape from predators more easily and could get access to more food resources."

He said that they "probably survived better in extreme environments as they were warm-blooded."

Ornithologist and evolutionary biologist Alan Feduccia of the University of North Carolina told Discovery News that "the research is important," due to what it reveals about the evolutionary history of birds.

Read more at Discovery News