The Yangtze River white dolphin may have lost a 20-million-year battle for survival. An expedition up the Yangtze River in search of the rare animal returned without a single sighting, leading the team leader to say the species, one of the oldest in the world, may be extinct, AP reported. The white dolphin or "baiji" may be the first aquatic species to disappear since the Caribbean monk seal 50 years ago. Although there may still be a few white dolphins in their native habitat, the numbers are not sufficient for them to breed enough to survive, said the co-leader of the expedition August Pfluger. "We have to accept the fact, that the baiji is functionally extinct. We lost the race," he said.