The white dolphin known as baiji, shy and nearly blind, dates back some 20 million years. Its disappearance is believed to be the first time in a half-century, since hunting killed off the Caribbean monk seal, that a large aquatic mammal has been driven to extinction.
Source: China's white dolphin called extinct after 20 million years - CNN.com
My experience with China tells me I probably had baijii as part of a meal on my last visit. I ate almost everything else that walks, crawls, fly's, swims, or slithers. And everyone knows, if they can sell it to you, they will. It was all good too - except the snails. The snails are a definite pass the next time around (which should be January).
Of course, most people blame the Baiji's extinction on the Three Gorges Dam, and rightly so.
Here is a link to Baiji.org. They have the whole depressing story.