The Yangtze river dolphin has now become one of the many species of animals that is now extinct. The Yangtze river dolphin was also called the baiji, chinese river dolphin and whitefin dolphin. It was a species of dolphin that was only found in the Yangtze river in China. This species of dolphin was one of if not the first species of dolphin that have ever died out of unnatural causes. The yangtze river was a highly polluted river. This is because the river was highly populated by humans whom polluted the water which ended out killing every last individual Yangtze river dolphin. According to the fossil records palaeontologists and scientists both think that they had been on this planet for about 25 million years ago. The speed that the Yangtze river dolphin would normally swim at was 6-9mph, that is the same as 10-15kph. However when the Yangtze river dolphin was trying to escape from something they could reach speeds of up to 60kph (37mph). But because of their poor vision and hearing they would mainly rely on their sonars to help them see where things were. All dolphins have a thing called sonar where they can see things in their minds by making a sort of clicking and chirping noise that will bounce back to them off objects so that they can tell where objects are in the water. And most dolphins including the Yangtze river dolphin will turn their sonar vision off when they are in familiar waters.
The yangtze river dolphin is one of four species of dolphins that have made their habitat only in freshwater.