The hummingbird hovers and rotates as handily as a helicopter; the swift glides and loops all day without landing. How did these closely related animals develop such different flying techniques? Researchers are gleaning clues from the fossil (left) of a new bird species that lived 50 million years ago. At 12 cm, Eocypselus rowei, discovered in Wyoming by commercial fossil hunters, is built on the same small scale as hummingbirds (upper right) and swifts (lower right), its modern-day cousins. The specimen's fossilized feathers—an unusual find that delighted researchers—show that its wings were somewhere in between the swift's superlong flappers and the hummer's comparatively short ones. The fossil's petite size suggests that birds in this family started to shrink early, researchers report online today in the Proceedings of the Royal Society B, and that hummingbirds and swifts evolved separately, rather than one giving rise to the other. Fossilized pigment cells suggest that the new species' plumage was glossy black, maybe even iridescent. But maybe only its feathers were showy: The bird probably wasn't a superstar of the air, instead perching for much of the day and making limited flights to nab insects.
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