''Palaeeudyptes klekowskii'' is an extinct

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), ...

of the

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 ...

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 ...

Palaeeudyptes ''Palaeeudyptes'' is an extinct genus of large penguins, currently containing four accepted species. They were probably larger than almost all living penguins, with the smaller species being about the size of an emperor penguin, and the largest s ...

''. It was previously thought to have been approximately the size of its congener ''

Palaeeudyptes antarcticus ''Palaeeudyptes antarcticus'', also referred to as the narrow-flippered penguin, is the type (zoology), type species of the extinct penguin genus ''Palaeeudyptes''. It was a huge species, albeit probably with a large size variation. Although the ...

'', somewhat larger than the 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 ...

, but a 2014 study showed it was in fact almost twice as tall, earning it the nickname “Mega Penguin”. Its maximum

length Length is a measure of distance. In the International System of Quantities, length is a quantity with Dimension (physical quantity), dimension distance. In most systems of measurement a Base unit (measurement), base unit for length is chosen, ...

is estimated to be up to and maximum body mass up to . Knowledge of it comes from an extensive collection of

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 preserve ...

bones from the 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 ...

(34-37 MYA) of the

La Meseta Formation The La Meseta Formation is a sedimentary sequence deposited during much of the Paleogene on Seymour Island off the coast of the Antarctic Peninsula. It is noted for its fossils, which include both marine organisms and the only terrestrial vertebr ...

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. ...

. ''P. klekowskii'' was at first not recognized as a distinct species, and despite the coexistence of two so closely related species of similar size as '' Palaeeudyptes gunnari'' and ''P. klekowskii'' seeming somewhat improbable, the amount of fossil material suggests that the two species are indeed diagnosably different.

References

* Jadwiszczak, Piotr (2006): Eocene penguins of Seymour Island, Antarctica: Taxonomy. ''Polish Polar Research'' 27(1): 3–62
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* Myrcha, Andrzej; Jadwiszczak, Piotr; Tambussi, Claudia P.; Noriega, Jorge I.; Gaździcki, Andrzej; Tatur, Andrzej & Del Valle, Rodolfo A. (2002): Taxonomic revision of Eocene Antarctic penguins based on tarsometatarsal morphology. ''Polish Polar Research'' 23(1): 5–46
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* Myrcha, Andrzej; Tatur, Andrzej & Del Valle, Rodolfo A. (1990) A new species of fossil penguin from Seymour Island, West Antarctica. ''Alcheringa'' 14: 195–205. klekowskii Eocene birds Extinct penguins Cenozoic Antarctica Cenozoic animals of Oceania Extinct animals of Antarctica Cenozoic animals of Antarctica {{Sphenisciformes-stub