['Sabre-toothed Cat. Often called Sabre-toothed Tigers or Sabre-toothed Lions, they existed 55 million to 11,700 years ago.', 'Woolly Mammoth. An enormous mammal, believed to be closely related to the modern-day elephant. ... ', 'Dodo. ... ', 'Great Auk. ... ', 'Stellers Sea Cow. ... ', 'Tasmanian Tiger. ... ', 'Passenger Pigeon. ... ', 'Pyrenean Ibex. ... ']