Giant extinct seabirds, (Osteodontornis orri), artwork. Pair of Osteodontornis flying over water. Oteodontornis lived during the Miocene (23-7 million years ago). It had a wingspan of up to 6 metres, which makes it the second largest flying bird that ever lived, after Argentavis magnificens. It belonged to an extinct group of toothed seabirdsjavascript:OpenPromptedKeyWords() distantly related to modern day pelicans, frigatebirds and cormorants. Its long wings enabled it to soar large distances over water in the same manner as modern day albatrosses.