Penguin

Penguin
Gentoo penguin Pygoscelis papua
Scientific classification
Kingdom Information
Domain	Eukaryota
Kingdom	Animalia
Subkingdom	Bilateria
Phylum Information
Superphylum	Deuterostomia
Phylum	Chordata
Sub-phylum	Vertebrata
Infraphylum	Gnathostomata
Class Information
Superclass	Tetrapoda
Class	Aves
Sub-class	Neornithes
Infra-class	Neognathae
Order Information
Order	Spheniciformes
Family Information
Family	Spheniscidae
Genus Information
Genera	Aptenodytes Eudyptes Eudyptula Megadyptes Pygoscelis Spheniscus
Population statistics

Penguins are 21 species of flightless birds inhabiting the cold waters of the Southern Hemisphere, the most highly specialized of any aquatic bird.

Entymology

Penguins were discovered with the great explorations of the 16th century, as European sailors pushed southward into the Atlantic Ocean. The first species of penguin they may have encountered was the gentoo penguin (Pygoscelis papua), which inhabits Patagonia, the Falkland Islands and South Georgia. The similarity in shape, habits, and coloration to a bird they had already known as the penguin - the extinct great auk (Pinguinus impennis) - was striking, hence the transfer of the name. The word is possibly based upon the Welsh pen gwyn, referring to the white eye patch on the head of the auk; or upon pin-wing, in reference to both bird's rudimentary wings.

Description

Depending on the species, penguins are between 16 and 46 inches in length. The largest is the emperor penguin (Aptenodytes forsteri), which stands close to four feet tall and weighs in at nearly 90 pounds; the smallest is the little penguin (Eudyptula minor) at sixteen inches and two pounds. When standing, penguins have a fully-erect posture and tend to move about in a comically-awkward gait, or they "toboggan", i.e. they slide on their bellies when on the ice, using feet and wings to push themselves along.

The body is streamlined and tapered at both ends, with the feet acting as rudders. The wings are nearly-fused at the wrists and elbows, and the bones flattened, giving the wings a paddle-like shape. Despite being flightless, penguins still have a well-defined keel sternum and powerful wing muscles, enabling the birds to move about in the water effortlessly, cruising at ten knots, yet capable of bursts in excess of twenty knots.

Coloration is similar to not just the great auk, but to orcas and several species of shark, in that they are countershaded (dark above, white below); the pattern is a type of camouflage, making them disappear in the dark depths of the sea when viewed from above, or blend in with the light patterns of the surface when viewed from below.

Phylogeny

• Family Spheniscidae

Subfamily Spheniscinae

Genus Aptenodytes

Emperor penguin, Aptenodytes forsteri

King penguin, Aptenodytes patagonicus

Genus Eudyptes

Chatham penguin, Eudyptes chathamensis (extinct)

Eastern rockhopper penguin, Eudyptes filholi

Erect-crested penguin, Eudyptes sclateri

Fiordland crested penguin, Eudyptes pachyrynchus

Macaroni penguin, Eudyptes chrysolophus

Northern rockhopper penguin, Eudyptes moseleyi

Royal penguin, Eudyptes schlegeli

Snares crested penguin, Eudyptes robustus

Western rockhopper penguin, Eudyptes chrysocome

Genus Eudyptula

Little penguin, Eudyptula minor

Genus Megadyptes

Waitaha penguin, Megadyptes waitaha (extinct)

Yellow-eyed penguin, Megadyptes antipodes

Genus Pygoscelis

Adelie penguin, Pygoscelis adeliae

Chinstrap penguin, Pygoscelis antarctica

Gentoo penguin, Pygoscelis papua

Genus Spheniscus

African penguin, Spheniscus demersus

Galapagos penguin, Spheniscus mendiculus

Humboldt penguin, Spheniscus humboldti

Magellanic penguin, Spheniscus magellanicus