Giant Bird, Jagged Grinhttp://news.nationalgeographic.com/news/2010/09/photogalleries/100915-giant-bird-wingspan-science-chilensis-teeth-pictures
Soaring above the oceans and mountains of what's now Chile between five and ten million years ago, the newly discovered species, named Pelagornis chilensis, was part of a prehistoric group known as the bony-toothed birds. The hollow spikes on the birds' beaks allowed the predators to grab slippery squid and fish from the ocean.
P. chilensis was identified based on an "exquisitely and exceptionally preserved" fossil skeleton that was found to be 70 percent complete, said study co-author David Rubilar of the Museo Nacional de Historia Natural in Chile.
The specimen includes the largest and most complete fossil bird wing yet excavated. Previous bony-toothed bird fossils included wings dug up in pieces, if it all, making it harder to accurately establish wingspan.
New giant bird species study appears in the Journal of Vertebrate Paleontology.
Fossil Seabird Skeleton
Because the two birds are structurally similar, studying a modern albatross's lifestyle is an excellent way to learn more about what the prehistoric seabird's daily life might have been like, Rubilar said.
In general, bony-toothed birds aren't well understood, because they had incredibly lightweight bones, which were often too brittle to withstand the fossilization process. But the P. chilensis specimen was discovered largely intact in a fine sandstone in northern Chile, Rubilar said.
And more such fossils may be coming, he added. "The fossils in this [sandstone layer] are abundant. ... Probably we'll find more and more complete specimens in the future."
Sawtooth Seabird Skull
Bony-toothed birds didn't chew their prey but used the false teeth to snatch fish and squid from the water's surface before swallowing them whole, said Estelle Bourdon, a researcher with the American Museum of Natural History, who was not involved in the study.
The birds, which scanned seas worldwide for more than 50 million years, likely went extinct about 2.5 million years ago, near the end of the Pliocene epoch, Bourdon said. (See a prehistoric time line.)
Although the giant seabirds "would have looked like creatures from Jurassic Park," they're true birds and not flying reptiles, lead author Gerald Mayr, of the Forschungsinstitut Senckenberg in Germany, said in a statement. In fact, he added, it's possible some of the last living members of P. chilensis existed at the same time as the earliest human ancestors in North Africa.
Giant Wingspan, Giant Glider
The shape of the species' arm bones shows that P. chilensis couldn't rotate its wings to flap and provide lift, Rubilar said. Instead, the seabird "just opened its arms" and—like modern Andean condors—caught updrafts rising from the Andes to become airborne and stay aloft for miles.
Modern albatrosses, the largest of which are about two-thirds the size of P. chilensis, can travel hundreds of miles without flapping.
Seabird Seen From Above
The new study shows that the arm bone of P. chilensis is nearly 40 percent longer than that of Argentavis magnificens, the largest known flying bird, which lived in Argentina six million years ago, study co-author Rubilar said. (See "Largest Flying Bird Could Barely Get off Ground, Fossils Show.")
But Argentavis likely had longer feathers, he noted, which means it holds on to the wingspan record—for now.