Birds With 20-Foot Wingspans Once Patrolled the Skies of Antarctica - Gizmodo

But this newly described bird, with wings stretching nearly 20 feet (6 meters), is the stuff of imagination.

Living during the Eocene between 50 million and 40 million years ago, this oversized pelagornithid, or “bony-toothed” bird, prowled the Antarctic skies in search of squid and fish, according to research published today in Scientific Reports.

As the authors sum up in their new paper, “these Antarctic fossils demonstrate the early evolution of giant body size in [pelagornithids], and they likely represent not only the largest flying birds of the Eocene but also some of the largest [flying] birds that ever lived,” featuring wingspans between 16.4 and 19.7 feet (5 and 6 meters).

Indeed, these birds are comparable to other extinct giants, namely Pelagornis sandersi (another pelagornithid), with its 20- to 24-foot wingspan (6 to 7.3 meters), and Argentavis magnificens, which had a wingspan measuring 23 feet (7 meters).

The species described in the new study is important in that it appeared far earlier in evolutionary history than these other avian giants (P. sandersi, for example, appeared between 25 million and 28 million years ago).

Pelagornithids were a successful group of bony-toothed birds that went extinct 2.5 million years ago following a 60-million-year reign.

The giant pelagornithid described in the new study dates back to at least 50 million years ago, which is significant from an evolutionary perspective.

“In a lifestyle likely similar to living albatrosses, the giant extinct pelagornithids, with their very long-pointed wings, would have flown widely over the ancient open seas, which had yet to be dominated by whales and seals, in search of squid, fish and other seafood to catch with their beaks lined with sharp pseudoteeth,” explained Stidham in the UC Berkeley release.