''Palaeeudyptes antarcticus'', also referred to as the narrow-flippered penguin, is the type

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of the

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

penguin Penguins (order (biology), order List of Sphenisciformes by population, Sphenisciformes , family (biology), family Spheniscidae ) are a group of Water bird, aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: on ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''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 high in life (''i.e.'' somewhat larger than an

emperor penguin The emperor penguin (''Aptenodytes forsteri'') is the tallest and heaviest of all living penguin species and is endemic to Antarctica. The male and female are similar in plumage and size, reaching in length and weighing from . Feathers of th ...

), 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 The tarsometatarsus is a bone that is only found in the lower leg of birds and some non-avian dinosaurs. It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) and meta ...

( BM A.1084) found in the Late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

Otekaike Limestone (23-28, possibly up to 34 MYA) at

Kakanui The small town of Kakanui lies on the coast of Otago, in New Zealand, fourteen kilometres to the south of Oamaru. The Kakanui River and its estuary divide the township in two. The part of the settlement south of the river, also known as Kakanui ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. An older date seems quite possible in fact as other bones have now been recovered from the Late

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

(34-37 MYA) of the

La Meseta Formation The La Meseta Formation is a sedimentary sequence deposited during the Eocene. The formation is found on Seymour Island, Antarctica. Description La Meseta Formation lies unconformably on the Cretaceous Lopez de Bertodano Formation. It is an app ...

Seymour Island Seymour Island or Marambio Island, is an island in the chain of 16 major islands around the tip of the Graham Land on the Antarctic Peninsula. Graham Land is the closest part of Antarctica to South America. It lies within the section of the isla ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

(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. This remains the only

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

unequivocally assigned to this species, but numerous other bones have been found that may belong to it too. These fossils were once uncritically considered as being from ''P. antarcticus'', merely because other large penguins were not known at that time, but have not been subject to scientific review according to modern standards. While some of these bones are now known to belong to other species, a large number are not unequivocally assignable to either ''P. antarcticus'' or ''P. marplesi'', being intermediate in size (Simpson, 1971), lending support to the theory that these taxa were in reality a single species.

References

* Huxley, Thomas Henry (1859): "On a Fossil Bird and a Fossil Cetacean from New Zealand". '' Quarterly Journal of the Geological Society of London'' 15: 670–677. * Simpson, George Gaylord (1946): "Fossil Penguins". ''

Bulletin of the American Museum of Natural History The ''Bulletin of the American Museum of Natural History'' is a peer-reviewed scientific journal in the fields of zoology, paleontology, and geology. It is part of a group of journals published by the American Museum of Natural History, in whic ...

'' 87: 7-99
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* Simpson, George Gaylord (1971): "A Review of the Pre-Pleistocene Penguins of New Zealand". ''Bulletin of the American Museum of Natural History'' 144: 319–378
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* Tambussi, C. P.; Acosta Hospitaleche, C. I.; Reguero, M. A. & Marenssi, S. A. (2006): "Late Eocene Penguins from West Antarctica: Systematics and Biostratigraphy". '' Geological Society, London, Special Publication'' 258: 145–161. {{Taxonbar, from=Q1064965 antarcticus Oligocene birds Extinct penguins Cenozoic Antarctica Cenozoic animals of Oceania Extinct animals of Antarctica Extinct birds of New Zealand Cenozoic animals of Antarctica