A chicken-size dinosaur sporting four wings may have glided through the skies some 155 million years ago, researchers say based on exceptionally well-preserved remains of the feathered beast.
The first specimen of this dinosaur was discovered last December and at the time thought to be a primitive bird. But after examination of the more complete and better preserved remains discovered in Liaoning, China, researchers say the animal belongs to the dinosaur group called maniraptorans thought to be closely related to birds. The dinosaur, called Anchiornis huxleyi, is now considered the oldest bird-like dinosaur to date, say the researchers.
The finding, published in the Sept. 24 issue of the journal Nature, sheds light on the transition from non-avian dinosaurs to birds and suggests birds’ ancestors sported four wings, according to the study researchers.
“This new find suggests that dinosaurs with flight feathers appear at least about 160 [million] years ago and birds’ direct ancestors are probably four-winged animals,” said study researcher Xu Xing of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences in Beijing.
Long feathers covered the dinosaur’s arms, tail and feet. “Their feathers are very similar to flight feathers of modern birds, but are symmetrical,” Xu told LiveScience. “It is likely that these feathers are used for gliding.”
Scientists think birds evolved from maniraptors some 150 million years ago during the Jurassic period, which lasted from about 206 million to 144 million years ago.
One argument against such a claim involves the timing of the transition, with naysayers suggesting bird-like dinosaurs appear too late in the fossil record to be true ancestors of birds. Essentially, that there wasn’t enough time for such a transition to occur.
But A. huxleyi lived about 30 million years before the feathered dinosaur Microraptor and about 5 million years before the oldest known bird, Archaeopteryx, the researchers say. This earlier date for the emergence of feathered dinosaurs undermines the claims that birds lacked enough time to evolve from dinosaurs. — LiveScience