Four-winged bird

Four-winged bird

Four-winged bird, Paleontologists say the ancestor of the modern crow and turkey was a four-winged bird: In addition to the normal flappers, it had plumed legs which probably helped with aerial guidance.

Eleven samples culled from the vast fossil stores of China's Shandong Tianyu Museum of Nature show well-preserved feathers in five different species of early birds and birdlike dinos. Plush leg feathers have previously only been spotted in fossils of flying dinosaurs, such as the four-winged Microraptor.

Xing Xu, a paleontologist at the Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology, was the first to point out fossil evidence of Microraptor's leggy plumage. He also led the team behind the latest findings, indicating that downy legs were shared by groups of early birds in the Lower Cretaceous period, 100 million to 150 million years ago. During that era, the birds were almost indistinguishable from the tiny dinos, except for differences in the tail structure and other details.

"This is what the ancestors of robins and chickens all went through," Thomas Holtz, a paleontologist at the University of Maryland told NBC News. "It tells us that we can look at animals like Microraptor and Anchiornis and they're still giving us information about modern birds."

The fact that Xu and his team found evidence of leg feathers in a few different species of different sizes tells Holtz that leg plumage was fairly common. "We’re really seeing how widespread this condition was," he says. "It’s really clarifying that it isn’t a weird side branch."

When Microraptor and other feathered dinosaurs were spotted, their appearance strongly hinted that they were precursors to modern birds. The question at the time, Holtz explained, was: "Were we seeing something that was common, that was at the base of the family tree of birds and dinos? Or were they independent?" The new samples provide more evidence to strengthen the link.

None of the groups of early birds that Xu and team describe is new. But this is the first time feathers have been identified, partly because the fossils have been preserved so well. The group presented its work in the journal Science on Thursday.

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