Giant bird, giant dig

The specimen was so large that it had to be dug out with a backhoe. "The upper wing bone alone was longer than my arm," Ksepka said in a statement.

The specimen, which consisted of multiple wing and leg bones and a complete skull, was very well-preserved, a rarity because of the paper-thin nature of the bones in these birds. Its beak possessed bizarre toothlike spikes that lined the upper and lower jaws, revealing the bird was a previously unknown species of pelagornithid, an extinct group of giant seabirds known for these "pseudo-teeth."

"These pseudo-teeth were not made with enamel like true teeth are, but were projections of bone from the jaw," Ksepka said. "They are very conical and pointed, which suggests they were used for piercing prey. The most likely source of food for these birds were fish and squid near the surface of the water."

This pelagornithid lived 25 million to 28 million years ago. "During this time, global temperatures were substantially warmer than they are today, and sea levels were higher, since there was less ice at the poles," Ksepka said. "Charleston, where this fossil was found, is a lovely city today, but back then it was completely underwater."

Pelagornithids lived all over the globe for tens of millions of years, but vanished just 3 million years ago, and paleontologists remain uncertain as to why.

"Pelagornithids were once found on every continent, including Antarctica," Ksepka said. "Pelagornithids were like creatures out of a fantasy novel — there is simply nothing like them around today." [Top 10 Beasts and Dragons: How Reality Made Myth]

The paper-thin hollow bones, stumpy legs and giant wings of P. sandersi hinted the bird flew. However, its size exceeded what some models suggest were the theoretical limits for flying birds.