Great auk (Pinguinus impennis), artwork. This flightless bird inhabited the north Atlantic, breeding on rocky islands. It grew up to 85 centimetres tall and weighed around 5 kilograms. It was an excellent swimmer and hunted fish and crabs as well as feeding on plankton. It became extinct in the 19th century, largely due to overfishing for its down. Image first published in 1893.