May 23, 2016

By Shaena Montanari

A sea bird with a 21 foot wingspan and teeth made of bone may sound like something out of science fiction, but these behemoths were real. Pelagornithids, or bony-toothed birds, were bizarre birds with enormous wingspans and extremely light bones—and now a team of Argentinian paleontologists has discovered what may be one of the oldest and largest bony-toothed birds yet in Antarctica. This new research was published this month in the Journal of Paleontology.

Bony-toothed birds were quite the cosmopolitan group between about 58 million to 2.5 million years ago, living all over the world from Africa to Europe to Antarctica. Their name is derived from the strange tooth-like projections on the edges of their beaks—not true teeth, but rather extra growth of the upper jaw bones that could have been useful for holding soft prey like squid or small fish. It is unlikely they ate anything hard, as “teeth” made of bone are not robust and break quite easily.

Not all pelagornithids were gigantic, some had wingspans more on the order of 5-7 feet, but there seems to have been two main varieties in Antarctica during the Eocene and both were extremely large. In fact, birds in this group kept their giant sizes until they went extinct 2.5 million years ago. They were able to fly because their bones were pneumatized—meaning air sacs from the lungs pushed into their thin walled bones creating empty cavities, making them extremely light.

For over 50 million years their giant wings darkened the skies until their extinction during the last 2.5 million years when the world climate began to shift. It is unknown why this mysterious group of birds went extinct, it is hypothesized ecological and climate change robbed them of the food necessary to support their large body size.

http://www.forbes.com/sites/shaenamontanari/2016/05/21/unbelievably-big-birds-called-antarctica-home-50-million-years-ago/#69a8b9041dda