Fossil skull of extinct St Helena Petrel
Pterodroma rupinarum  

This extinct medium-sized gadfly petrel was first noted by Bill Bourne, who found a skull in the British Museum collected by Lieut. Turton in the 19th century. It proved to be abundant in the fossil deposits and was evidently a prominent member of the seabird community for several million years prior to 1502. Storrs Olson, who named the species, concluded that it is related to a group of species previously known only from the Indian Ocean and Pacific, including Pterodroma rostrata.. The members of this group have a strongly down-angled bill that distinguishes them from other members of the genus.