Rare White Dolphin Declared As Extinct

"A rare, nearly blind white dolphin that survived for millions of years is effectively extinct, an international expedition declared Wednesday after ending a fruitless six-week search of its Yangtze River habitat.The baiji would be the first large aquatic mammal driven to extinction since hunting and overfishing killed off the Caribbean monk seal in the 1950s." - washpost

They don't mean that one single blind white dolphin survived for 20 million years, rather the entire species existed for that long.