At 75 centimetres, the flightless Great Auk (Pinguinus impennis or Alca impennis) was the largest of the auks. It was hunted for food and down for mattresses from at least the 8th century. It is clasified as the only species in the genusPinguinus.
They were excellent swimmers, using their wings to swim underwater. Unlike other auks, however, the Great Auk could not fly, which is what made it so vulnerable to humans.
The Great Auk, in Welshpen gwyn ('white head', referring to the prominent white patch on the head), was the origin the name "penguin". When explorers discovered similar- looking birds in the southern hemisphere, the name was applied to them as well.