''Archaeospheniscus'' is an

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 ...

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 ...

of large

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 ...

s. It currently contains three

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 ...

, known from somewhat fragmentary remains. ''A. wimani'', the smallest species (about the size of a

gentoo penguin The gentoo penguin ( ) (''Pygoscelis papua'') is a penguin species (or possibly a species complex) in the genus ''Pygoscelis'', most closely related to the Adélie penguin (''P. adeliae'') and the chinstrap penguin (''P. antarcticus''). The ear ...

), was found in Middle or 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' ...

strata (34-50 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 ...

, whereas the other two, about the size of a modern

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 ...

, are known from bones recovered from 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 ...

Kokoamu Greensand The Kokoamu Greensand is a geological formation found in New Zealand. It is a fossil-bearing, late Oligocene, greensand rock unit of the eastern South Island, especially the Waitaki District of North Otago and the southern Canterbury region. The ...

Formation (27-28 MYA) at

Duntroon, New Zealand Duntroon (from gd, Dùn Treòin) is a small farming-town in the Waitaki District of New Zealand's South Island. Although traditionally considered a North Otago town, it is located within the farthest southern reaches of Canterbury. Just nort ...

. The genus is one of the earliest known primitive penguins. Its

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

is still very slender, between the form seen in ordinary bird wings and the thickened condition found in modern penguins. On the other hand, the

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 ...

shows a peculiar mix of characters found in modern and primitive forms. Whether this signifies that the genus is an ancestor of modern taxa or represents a case of

parallel evolution Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.Zhang, J. and Kumar, S. 1997Detection of convergent and paral ...

is unknown.

Species

* '' Archaeospheniscus lowei'' * '' Archaeospheniscus lopdelli'' * '' Archaeospheniscus wimani''

References

* Jadwiszczak, Piotr (2006): Eocene penguins of Seymour Island, Antarctica: Taxonomy. ''Polish Polar Research'' 27(1): 3–62
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* Marples, Brian J. (1952): Early Tertiary penguins of New Zealand. ''New Zealand Geol. Surv., Paleont. Bull.'' 20: 1-66. * 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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{{Taxonbar, from=Q1062897 Bird genera Extinct penguins Eocene birds Oligocene birds Prehistoric birds of Antarctica Fossil taxa described in 1952 Taxa named by Brian John Marples