Palaeeudyptes antarcticus, also referred to as the narrow-flippered penguin, is the type species of the extinct penguin genus Palaeeudyptes. It was a huge species, albeit probably with a large size variation. Although the size range can only be loosely estimated, the birds seem to have stood between 43 and 55 inches (1.1 and 1.4 m) high in life (i.e. somewhat larger than an emperor penguin), placing this species and its congener Palaeeudyptes marplesi among the largest penguin species known. It was the last known Palaeeudyptes species, and although the exact time when it lived is not precisely determined, it may have evolved from P. marplesi, or they might even have been a single species which slightly decreased in size over time.
P. antarcticus was the first fossil penguin to become known to science. It was described from a single, slightly damaged, tarsometatarsus (BM A.1084) found in the Late Oligocene Otekaike Limestone (23-28, possibly up to 34 MYA) at Kakanui, New Zealand. An older date seems quite possible in fact as other bones have now been recovered from the Late Eocene (34-37 MYA) of the La Meseta Formation on Seymour Island, Antarctica (Tambussi et al., 2006), but given the considerable distances in age and range involved, it is not completely certain that the bones belong to a single species.
