Pelagornis sandersi
Pelagornis sandersi is an extinct species of flying bird, whose fossil remains date from 25 million years ago, during the Chattian age of the Oligocene. The sole specimen of "P. sandersi" has a wingspan estimated between , giving it the largest wingspan of any flying bird yet discovered, twice that of the wandering albatross, which has the largest wingspan of any extant bird (up to ). In this regard, it supplants the previous record holder, the also extinct "Argentavis magnificens". The skeletal wingspan (excluding feathers) of "P. sandersi" is estimated at while that of "A. magnificens" is estimated at . Some  scientists expressed surprise at the idea that this species could fly at all, given that, at between , it would be considered too heavy by the predominant theory of the mechanism by which birds fly. Dan Ksepka of the National Evolutionary Synthesis Center in Durham, North Carolina, who identified that the discovered fossils belonged to a new species, thinks it was able to fly in part because of its relatively small body and long wings, and because it, like the albatross, spent much of its time over the ocean. Discovery. The only known fossil of "P. sandersi" was first uncovered in  1983 at Charleston International Airport, South Carolina, discovered by James Malcom, while working construction building a new terminal there. At the time the bird lived, 25 million years ago, this area was an ocean. The bird is named after Albert Sanders, the former curator of natural history at Charleston Museum, who led the excavation. It currently sits at the Charleston Museum, where it was identified as a new species by Dan Ksepka in 2014. "Though no feathers survived, Ksepka extrapolated the mass, wingspan, and wing shape from the fossilised bones and fed them into a computer to estimate how the  bird might fly. A conservative estimate put the wingspan of "P. sandersi" at around 6.4 metres (21 feet)." Physiology. "P. sandersi" had short, stumpy legs, and was probably able to fly only by hopping off cliff edges. It has been estimated that it was able to fly at up to . Like all members of the Pelagornithidae, "P. sandersi" had tooth-like or knob-like extensions of the bill's margin, called "pseudo-teeth," which would have enabled the living animal to better grip and grasp slippery prey. According to Ksepka, "P. sandersi"s teeth "don’t have enamel, they don’t  grow in sockets, and they aren’t lost and replaced throughout the creature’s life span." Comparison to pterosaurs. While "P. sandersi" wingspan of is believed to be the largest known among birds, it is still far from the largest known flying animal. Flying pterosaurs such as "Hatzegopteryx" and "Quetzalcoatlus" are believed to have reached wingspans of up to. However, the wingspan of "P. sandersi" was similar to that of "Pteranodon", another large well-known pterosaur.