''Archaeospheniscus'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of large

penguin Penguins are a group of aquatic flightless birds from the family Spheniscidae () of the order Sphenisciformes (). They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a sm ...

s. It currently contains three

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, 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 earl ...

), was found in Middle or Late

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

strata (34-50 MYA) of the La Meseta Formation on

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 isl ...

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

, 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 Endemism in birds, endemic to Antarctica. The male and female are similar in plumage and size, reaching in length and weighing fr ...

, are known from bones recovered from the Late

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

Kokoamu Greensand Formation (27-28 MYA) at Duntroon, New Zealand. The genus is one of the earliest known primitive penguins. Its

humerus The humerus (; : humeri) 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 (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

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 bird bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) a ...

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 pa ...

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
PDf fulltext
* 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
PDF fulltext
{{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