The Field Museum unveiled the new find on Monday. It's a small fossil of the first known bird. It's not only the best of its kind ever found, it's also the only one on exhibit at any major museum.

Evidence of avian beginnings has been elusive in the fossil record because birds' light, hollow bones rapidly decompose. So far, the oldest-known bird fossil is the famous Archaeopteryx ...

"This fossil is so truly one-of-a-kind that I was awestruck from the moment I first saw ... of this early bird," Navalón said. Before this discovery, almost nothing was known about the ...

“The fossil is exciting,” said Eric Delson, a paleontologist at the American Museum of Natural History, who was not involved in the study. “It’s the first time we have significant remains ...