5 Yuan Baiji Dolphins

The baiji, or Yangtze River dolphin, was already functionally endangered when this coin was issued — fewer than a hundred individuals were estimated to survive in 1996. The species was declared extinct in 2006 following a survey that found none. China's commemorative wildlife series of the 1990s frequently highlighted animals whose protection campaigns were already failing, and the baiji became the first large aquatic mammal driven to extinction in modern times.