This week, scientists announced the discovery of two fossil specimens from China that they believe to be records of the oldest member of Ornithuromorpha, the branch of the avian evolutionary tree that contains modern birds. The new species, named Archaeornithura meemannae, was unveiled in a recent study published in Nature Communications.
Previously, the oldest-known Ornithuromorpha dated back 125 million years. But the new species is nearly 5 million years older.
Even with this blip in the evolutionary timeline, however, there are fossilized birds that are even more ancient. Archaeopteryx, which disappeared about 145 million years ago, still holds the record. “Currently, Archaeopteryx is still the oldest and most primitive bird," says Min Wang, leader of the study and paleontologist at the Chinese Academy of Sciences in Beijing, China.
The new fossils are characterized by feathers and short tails—defining features for Ornithuromorpha. “The relatively long legs and short wings as well as the less curved foot claws and toe proportions show that Archaeornithura represents a terrestrial bird, most likely a wading bird,” says co-author Zhonghe Zhou. “Feathers were well preserved [along] with some flight-related skeletal features, indicating that it was a good flier, much like modern birds.”
Despite this finding, however, Zhou believes there are more surprises in store in the search for Earth’s first modern bird. “Surely there should be some birds older than Archaeornithura meemannae,” he says. “There are still a lot of missing links in early avian evolution that await to be discovered in the future.”
Correction: The article previously stated that the newly discovered Archaeornithura meemannae is a direct ancestor to modern birds. That is incorrect—though Archaeornithura is in the same group as extant avians, it diverged from the ancestral line early on, and is not a direct ancestor of today’s birds. Some parts of the story, including the headline, have been updated to reflect this more accurate information.