Tiny Winged Fossil Reveals Origins of Speedy Swift and Hummingbird Flight

A tiny, winged fossil could shed light on the origins of swift and hummingbird flight. The bird fossil, which was discovered in Wyoming, offers clues to the precursors of the speedy wings that these species use.

The fossil itself is unusual. It has well-preserved feathers and possesses a skeleton that is nearly complete. The bird, when alive, would have been able to fit in the palm of a hand and probably weighed less than an ounce. Named Eocypselus rowei , the newly discovered species looks surprisingly similar to some of the modern birds of today.

In order to find out exactly where it fit on the bird family tree, researchers compared the specimen to extinct modern day species. After analysis, they discovered that the bird was probably an evolutionary precursor to the group of birds that includes today's swifts and hummingbirds.

Despite the fact that hummingbirds and swifts are related, though, there's a huge difference in wing shape between these two related groups. Hummingbird wings are short relative to their bodies. They're shaped for hovering, allowing the birds to flit from flower to flower and pause as they sip nectar. Swifts, one the other hand, are built for speed. They have super-long wings that allow them to glide and zoom through the air, but don't allow them to hover mid-flight. For years, scientists have puzzled over how swift and hummingbird flight came to be. Yet this new fossil could provide some evidence to reveal the origins of their wing shapes.

"This fossil bird represents the closest we've gotten to the point where swifts and hummingbirds went their separate ways," said lead author Daniel Ksepka in a news release. "[Based on its wing shape] it probably wasn't a hoverer, like a hummingbird, and it probably wasn't as efficient at fast flight as a swift."

Yet the researchers didn't only find out how this creature flew. Using a scanning electron microscope, they found carbon residues in the fossils that turned out to be fossilized melanomes. These tiny cell structures contain melanin pigments that give birds and other animals their color. After studying the remains, the researchers were able to tell that this ancient bird was probably black and may have had a glossy or iridescent sheen, like swifts living today.

The research could show the evolutionary root to both hummingbirds and swifts, though more studies are needed before any conclusions are drawn.

The findings are published in the journal Proceedings of the Royal Society B.