Prehistoric birds of Antarctica

Anthropornis is a genus of giant penguin that lived 45-33 million years ago, during the Late Eocene and the earliest part of the Oligocene.

Palaeeudyptes is an extinct genus of large penguins, currently containing four accepted species. They were probably larger than almost all living penguins, with the smaller species being about the size of an emperor penguin, and the largest species, Palaeeudyptes klekowskii, estimated to reach long (measuring tip of beak to tail) and weighed up to .

Archaeospheniscus is an extinct genus of large penguins. It currently contains three species, known from somewhat fragmentary remains. A. wimani, the smallest species (about the size of a gentoo penguin), was found in Middle or Late Eocene strata (34-50 MYA) of the La Meseta Formation on Seymour Island, Antarctica, whereas the other two, about the size of a modern emperor penguin, are known from bones recovered from the Late Oligocene Kokoamu Greensand Formation (27-28 MYA) at Duntroon, New Zealand.

Crossvallia is an extinct genus of penguins. It includes two species, C. unienwillia and ?C. waiparensis. Their anatomy suggests that the genus is closely related to the Anthropornithinae.