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 (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 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 nomenclat ...

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

Icadyptes salasi ''Icadyptes'' is an extinct genus of giant penguins from the Late Eocene tropics of South America. Etymology The genus name is a combination of "''Ica''" for the Peruvian region where the type species was found and "dyptes" from the Greek w ...

'', ''

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 slig ...

'', ''

Anthropornis nordenskjoeldi ''Anthropornis'' is a genus of giant penguin that lived 45-33 million years ago, during the Late Eocene and the earliest part of the Oligocene.Myrcha, A., Jadwiszczak, P., Tambussi, C.P., Noriega, J.I., Gazdzicki, A., Tatur, A., and Valle, R.A ...

'', and '' Pachydyptes ponderosus''. ''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 manufacture ...

feather Feathers are epidermal growths that form a distinctive outer covering, or plumage, on both avian (bird) and some non-avian dinosaurs and other archosaurs. They are the most complex integumentary structures found in vertebrates and a premier ...

ing, 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 media ...

and

wrist In human anatomy, the wrist is variously defined as (1) the Carpal bones, 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 ...

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 Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

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 them ...

and

pinnipeds Pinnipeds (pronounced ), commonly known as seals, are a widely range (biology), distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammal, marine mammals. They comprise the extant taxon, extant family (biology ...

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 the ...

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 recen ...

. 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 smaller islands. It is the sixth-largest island count ...

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 ...

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 southe ...

, and possibly

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, dating from the 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' ...

to the Late Oligocene; the Australian Middle Miocene genus ''

Anthropodyptes ''Anthropodyptes'' is a poorly known monotypic genus of extinct penguin. It contains the single species ''Anthropodyptes gilli'', known from a Middle Miocene humerus from Australia. The bone is somewhat similar to those found in members of the N ...

'' 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 gl ...

. 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 ''Delphinornis'' is an extinct genus of penguins that lived around the middle Eocene to the middle Miocene in Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarcti ...

'', '' Marambiornis'', and '' Mesetaornis'' do indeed belong into this subfamily, but it is just as probable that others, such as ''

Duntroonornis ''Duntroonornis parvus'', also referred to as the Duntroon penguin, is a genus and species of extinct penguin from the Late Oligocene of New Zealand. The penguin was relatively small, similar in size to the Fiordland crested penguin. It was des ...

'' and ''

Korora ''Korora oliveri'', also referred to as Oliver's penguin, is a genus and species of extinct penguin from the Waitakian Stage (Late Oligocene to Early Miocene) of New Zealand. It was relatively small and slender, similar in size to one of the l ...

'', 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 all ...

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