The earliest birds were pulling up worms at least 130 million years ago, newly discovered fossils have revealed – about 5 or 6 million years earlier than previously believed.
The two well-preserved specimens, named Archaeornithura meemannae, are now the oldest-known examples of the Ornithuromorpha “true bird” evolutionary line, which gave rise to birds as we know them today.
They were found in the Sichakou basin in Hebei, northeastern China, a regular spot for dinosaur discoveries.
Archaeornithura lived about 30 million years after the first dinosaur-bird hybrids appeared, such as Anchiornis, but those other evolutionary lines aren’t believed to have survived the mass extinction 66 million years ago which wiped out the dinosaurs.
Min Wang of the Chinese Academy of Science says the two fossils had “near-completely preserved plumage with anatomical features characteristic of an aerodynamic lifestyle and manoeuvrability during flight”.
They are missing feathers on their upper legs however, suggesting they spent much of their time wading, “consistent with other fossil bird species found in similar deposits”.
“Radiometric dating of the geological layers from which these fossils were extracted indicates these new specimens lived during the early Cretaceous period 130.7 million years ago, predating the last known specimens of this branch from the lower Cretaceous, 125 million years ago,” a release from scientific journal Nature said.
The discovery bumps the previous earliest-known species in the Ornithuromorpha line, Archaeorhynchus, to second place.