Has the world’s first bird fossil, a Jurassic era specimen some 150 to 160 million years old, been found in a museum cabinet in China? According to a report published Thursday in Nature by Chris Woolston, a single Aurornis xui was found in the Fossil and Geology Park museum in Yizhou, China, where it had apparently been for some time after having been brought there by a farmer.
Now a debate has erupted over whether or not the specimen is truly the world’s earliest known bird — or if it’s just another feathered dinosaur fossil.
Royal Belgian Institute of Natural Sciences in Brussels paleontologist Pascal Godefroit is the man who discovered the fossil. “In my opinion, it’s a bird,” he told Nature. But he admitted that his work is considered controversial because the “differences between birds and [non-avian] dinosaurs is very thin.”
Aurornis probably couldn’t fly. Instead, it was a glider. However, that isn’t a deal-killer, since many birds from widely separated families can’t fly — including penguins, ostriches, and even a parrot species, the kakapo.
However, it appears to be very primitive indeed, and whether or not you consider it a bird may depend on where you want to draw the line.
Luis Chiappe, a paleontologist at the Natural History Museum of Los Angeles County, said, “This is very birdlike, but it is not yet a bird.”
Of course, some paleontologists have made the same claim about Archaeopteryx, once popularly believed to be the oldest known fossil bird. A 2011 paper renewed the debate, saying that Archaeopteryx was a feathered dinosaur, but not a bird itself.
Since Archaeopteryx appears to be descended from Aurornis, if the Chinese specimen is accepted as a bird, Archaeopteryx will be too.
If Archaeopteryx is instead a Velociraptor-style feathered dinosaur and not a bird, then it would appear that powered flight evolved twice instead of just once.
To add to the confusion, in the modern world, if it has feathers, then it’s a bird.
Whatever the final taxonomy, Godefroit believed that museums like the one in Yizhou might hold hundreds of other new specimens waiting to be described.
Aurornis xui might be the first fossil bird only until we find one even older.
[Archaeopteryx “early bird” fossil photo by Elaine Radford]