GREENWICH, Conn. -- Daniel Ksepka, the new curator at the Bruce Museum in Greenwich, was amazed when a large drawer was pulled open a few years ago and he saw part of the upper wing bone of a bird fossil from 25 million years ago.
“It was way longer than my whole arm, and I said, 'This is something big,'” he said with a laugh Tuesday, recounting the moment when he first saw what is now described as the largest-ever flying bird, the Pelagornis sandersi.
Ksepka published his findings in the Proceedings of the National Academy of Sciences, and they were made public on Monday.
It was about three years ago that Ksepka, then working at the National Evolutionary Synthesis Center at Duke University in Durham, N.C., was invited to examine bird fossils discovered in 1983. The invitation came from Albert Sanders, the now-retired curator of the Charleston Museum, who found them while leading a team as the Charleston International Airport was undergoing an expansion.
However, Sanders was an expert in whale fossils and didn't realize the importance of the bird fossils, said Ksepka, pointing out that a huge number of fossils in collections around the world haven’t been examined.
In the case of the Charleston find, the bird fossils were placed in a drawer and put away -- but not forgotten.
When Sanders contacted Ksepka, he was intrigued by the time period of the fossils collected by Sanders' team.
“Fifty million years ago, we have remarkable fossil deposits where we have a great idea of what’s living in North America. Then, younger deposits, about 10 million years ago, we get another good set of deposits," he said. "But there is not much in between, and I thought this could potentially be important. What I did not know is that they had this gigantic bird there.”
Ksepka had to decide where to start. “There were a lot of questions to ask: ‘Was this a new species? And the answer is yes. So how did it fly?’ So that required a lot of computer modeling,” he said.
He believes the massive bird was a very efficient glider and was able to travel great distances as it searched for food. Ksepka believes the bird feasted on fish, based on the mouth, which is filled with tooth-like spikes.
Ultimately, the bird died out for unknown reasons. But it was part of a family of birds that survived for a very long time -- from a period after the dinosaurs died out until just before human's ancestors appeared on the scene, Ksepka said.
The family of birds thrived from about 55 million years ago to about three million years ago.
“When you do the math, it is more than 50 million years (they lived) as a very successful group. They were around and then they vanished," he said. "I don’t think there is any single cause that we can point to as a smoking gun. Something went wrong and it is a shame because we barely just missed them."