What is the biggest flying bird in the world?

Pelagornis sandersi was the biggest flying bird in the world. Discovered in 1983 near Charleston, S.C., the bird lived some 25 to 28 million years ago and had an estimated wingspan of 20 to 24 feet. It overtakes the previous record holder, Argentavis magnificens, which had a 3-meter wingspan.

P. sandersi had stumpy legs, long efficient gliders and paper-thin hollow bones that allowed the huge bird to glide comfortably in the air but made it awkward for the bird to land. A well-preserved P. sandersi specimen is displayed in the Charleston Museum. It is named after Albert Sanders, the retired curator of the Charleston Museum and the one who led the excavation of the bird's fossils.