What it is
The baiji was a long-beaked freshwater dolphin of the Yangtze. A 2006 range-wide survey found none, and the species is widely treated as functionally extinct. IUCN still lists it as Critically Endangered (Possibly Extinct), not as formal EX, because a last individual cannot be ruled out with certainty.
Range
The middle and lower Yangtze River, China. It did not occur at sea.
What happened
Rolling-hook fisheries, ship strikes, dams, and pollution removed quiet water. The last confirmed sighting is 2002. The 2006 expedition is the main basis for calling the species gone. This entry sits in Extinct because the animal is missing from the river; the IUCN code is the more cautious one.
When / status
Last confirmed 2002. Functionally extinct after the 2006 survey; IUCN CR (Possibly Extinct).
Human role
Industrial use of the Yangtze — bycatch, traffic, and dams — left no room for a river dolphin.
Sources
IUCN Red List (Lipotes vexillifer, CR Possibly Extinct); Turvey et al. 2006 survey.