 "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.The genus is one of the earliest known primitive penguins.Its humerus is still very slender, between the form seen in ordinary bird wings and the thickened condition found in modern penguins.