Skull of Fregata aquila - top to bottom - 1) Skull and mandible of Fregata aquila Left lateral view 2) View of skull from above 3) View of mandible from above 4) View of skull from below
Date 1902
Source Shufeldt, R.W. 1902. The Osteology of the Steganopodes. Memoirs of the Carnegie Museum. 1(3):109-223.
Author R.W. Shufeldt
Source: https://commons.wikimedia.org/wiki/File:Fregata_aquila_skull.jpg

The Ascension frigatebird (Fregata aquila) is a seabird of the frigatebird family Fregatidae which breeds on Boatswain Bird Island and Ascension Island in the tropical Atlantic Ocean.