Palaeeudyptinae, the giant penguins, is a

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

subfamily of prehistoric

penguin Penguins ( order Sphenisciformes , family Spheniscidae ) are a group of aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapt ...

s. It includes several

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial ...

of medium-sized to very large species, such as '' Icadyptes salasi'', ''

Palaeeudyptes marplesi Marples' penguin (''Palaeeudyptes marplesi'') was a large species of the extinct penguin genus ''Palaeeudyptes''. It stood between high in life, larger than the present emperor penguin. The precise relationship between this species and the sli ...

'', '' Anthropornis nordenskjoeldi'', and ''

Pachydyptes ponderosus ''Pachydyptes'' is an extinct genus of penguin. It contains the single species ''Pachydyptes ponderosus'', the New Zealand giant penguin. This taxon is known from a few bones from Late Eocene (37 to 34 MYA) rocks in the area of Otago, which wer ...

''. ''Icadyptes'' reached in height, while members of ''Palaeeudyptes'' and ''Anthropornis'' grew even taller and were some of the largest penguins to have ever existed. The massive ''P. ponderosus'' may have weighed at least as much as an adult human.

Lineage

They belonged to an

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

ary lineage more primitive than modern penguins. In some taxa at least, the wing, while already having lost the

avian Avian may refer to: *Birds or Aves, winged animals * Avian (given name) (russian: Авиа́н, link=no), a male forename Aviation *Avro Avian, a series of light aircraft made by Avro in the 1920s and 1930s * Avian Limited, a hang glider manufactu ...

feathering, had not yet transformed into the semi-rigid flipper found in modern penguin species: While the

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

and the

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

were already flattened to increase propelling capacity, the

elbow The elbow is the region between the arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), and the lateral and the m ...

and

wrist In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal ...

joint A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw ...

s still retained a higher degree of flexibility than the more rigidly lockable structure found in modern genera. The decline and eventual disappearance of this subfamily seems to be connected to increased competition as mammal groups such as

cetaceans Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel t ...

and

pinnipeds Pinnipeds (pronounced ), commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the walrus) ...

became better-adapted to a marine lifestyle in the

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 ...

and

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

. The members of this subfamily are known from fossils found in

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 List of islands of New Zealand, smaller islands. It is the ...

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 co ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

, and possibly Australia, dating from the Middle or Late

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

to the Late Oligocene; the Australian Middle Miocene genus '' Anthropodyptes'' is also often assigned to this subfamily, as are the remaining genera of primitive penguins except those from

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and ...

. Indeed, it was long assumed that all prehistoric penguins which cannot be assigned to extant genera belonged into the Palaeeudyptinae; this view is generally considered obsolete today. It is likely that some of the unassigned New Zealand/Antarctican/Australian genera like '' Delphinornis'', '' Marambiornis'', and '' Mesetaornis'' do indeed belong into this subfamily, but it is just as probable that others, such as '' Duntroonornis'' and '' Korora'', represent another, smaller and possibly somewhat more advanced lineage. The Palaeeudyptinae as originally defined (Simpson, 1946) contained only the namesake genus, the remainder being placed in the Anthropornithidae. The arrangement followed here is based on the review of Marples (1962) who

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are al ...

ized the two, with updates to incorporate more current findings.

References

* Marples, B. J. (1962): Observations on the history of penguins. ''In:'' Leeper, G. W. (ed.), ''The evolution of living organisms''. Melbourne, Melbourne University Press: 408–416. * Simpson, George Gaylord (1946): Fossil penguins. ''Bull. Am. Mus. Nat. Hist.'' 87: 7-99
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Bird subfamilies Extinct penguins Paraphyletic groups {{paleo-bird-stub