Fossil of biggest-ever flying bird reveals aerodynamic overachiever

Fossil of biggest-ever flying bird reveals aerodynamic overachiever

By Rex Graham

Scientists identified fossilized remains of an ancient bird with a 24-foot wingspan, the biggest-ever flying bird. The fossilized remains were unearthed in 1983 in Charleston, South Carolina, during excavation for the Charleston International Airport.

Pelogornis sandersi, birdsnews.com

This is an artist’s drawing of the new fossil species Pelagornis sandersi, which may be the biggest-ever flying bird ever found. (Art by Liz Bradford)

“The upper wing bone alone was longer than my arm,” said Dan Ksepka of the National Evolutionary Synthesis Center in Durham, North Carolina. Ksepka was a co-author of a paper published online the week of July 7, 2014, in the journal Proceedings of the National Academy of Sciences. Ksepka is an expert on the evolution of avian flight.

Albatross Size XXL

The new creature to science surpasses the previous record holder – a long-extinct bird named Argentavis magnificens. P. sandersi was twice as big as the Royal Albatross, the largest flying bird today.

Now in the collections at the Charleston Museum, the strikingly well-preserved specimen consisted of multiple wing and leg bones and a complete skull. Its sheer size and telltale beak allowed Ksepka to identify the find as a previously unknown species of pelagornithid, an extinct group of giant seabirds known for bony tooth-like spikes that lined their upper and lower jaws, according to a news release by the National Evolutionary Synthesis Center.

Drawing of P, birdsnews.comelagornis sandersi

The long-extinct Pelagornis sandersi was twice as big as the Royal Albatross, the largest flying bird today. (Art: Liz Bradford)

The bird was named ‘Pelagornis sandersi‘ in honor of retired Charleston Museum curator Albert Sanders, who led the fossil’s excavation. P. sandersi lived 25 to 28 million years ago in the Paleogene Period of the Cenozoic Era. That was roughly 40 million years after dinosaurs vanished.

Extremely efficient glider

Ksepka wrote that the creature was an extremely efficient glider, with long slender wings that helped it stay aloft despite its enormous size. It had paper-thin hollow bones, stumpy legs and giant wings. While it was surely at home in the air, it must have been awkward on land.

The bird is an aerodynamic overachiever. It exceeded what some mathematical models say is the maximum body size possible for flying birds. It’s not clear how the massive bird took off.

Fossil flight simulations

Like Argentavis, whose flight was described by a computer simulation study in 2007, P. sandersi may have run downhill into a headwind. Ksepka said it may have taken advantage of air gusts to get aloft, like a hang glider. Ksepka fed the bird’s dimensions into a computer program designed to predict flight performance given various estimates of mass, wingspan and wing shape. P. sandersi was probably too big to simply launch itself into the air from a standstill, analyses show.

Once airborne, Ksepka’s simulations suggest that the bird’s long, slender wings made it an incredibly efficient glider. By riding on air currents that rise up from the ocean’s surface, P. sandersi was able to soar for miles over the open ocean without flapping its wings, occasionally swooping down to the water to feed on soft-bodied prey like squid and eels.

Dan Ksepka

Paleontologist Dan Ksepka examines the fossilized skull of what may be the biggest-ever flying bird ever found. (Photo: Dan Ksepka)

“That’s important in the ocean, where food is patchy,” said Ksepka, who is now Curator of Science at the Bruce Museum in Greenwich, Conn.

Researchers hope the find will help shed light on why the family of birds that P. sandersi belonged to eventually died out, and add to our understanding of how the giants of the skies managed to fly.

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