A fossil feather from the age of dinosaurs may explain why only some birds survived

This fossilized feather dates back 66 million years to the late Cretaceous. "It is, without a doubt, the best feather we've ever found from the age of dinosaurs," says Jingmai O'Connor, an associate curator at the Field Museum of Natural History. Nate Carroll hide caption

In 2016, David DeMar was doing field work in the rocky badlands of Montana in what's known as the Hell Creek Formation.

"We all get down on our hands and knees," he recalls. "And I start crawling up the hill and I noticed this little dark, round object on the ground. It was kind of odd."

DeMar, a lab manager at the Burke Museum in Seattle, picked up the cherry-sized fossil.

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"I start looking at the surface of it," he says. "And then I rolled it over and I was like, 'You got to be kidding me.'"

Embedded in a small crack on the surface was a tiny fossilized branching structure. As it turned out, this was the first fossilized feather from this part of the world.

In addition, "it is, without a doubt, the best feather we've ever found from the age of dinosaurs," says Jingmai O'Connor , a bird expert and an associate curator of fossil reptiles at the Field Museum of Natural History in Chicago.