A rare river dolphin has been officially classified as a new species.
The Bolivian river dolphin has been acknowledged as a separate species to the more widely-known Amazon River dolphin.
The formal announcement was made at a conservation workshop in Santa Cruz de la Sierra in Bolivia.
The Bolivian dolphin (Inia boliviensis) was immediately adopted by the Bolivian government as a symbol of the country's conservation efforts.
The Bolivian species is smaller and a lighter grey in colour than the other species and has more teeth. It lives only in the Bolivian Amazon and is isolated from the other Amazon River dolphins, separated by a series of 18 rapids between Bolivia and Brazil.
The boto or Amazon pink river dolphin (Inia geoffrensis) lives exclusively in the freshwater river systems of the Amazon and Orinoco Rivers. The largest of all river dolphins, botos vary from grey to pink and can even change colour, becoming pinker if very active.
Unusually for a dolphin, they have flexible necks and can turn their heads from side to side, weaving between the branches of flooded forests during the wet season.
Both species are hailed as important indicator species for the health of the entire river ecosystem, but are under serious threat from pollution and fisheries.
The adoption of the new species was welcomed by the Whale and Dolphin Conservation Society (WDCS) which warned of the threats facing endangered dolphins.
The world's leading Amazon river dolphin specialist, Fernando Trujillo, who is a researcher funded by the WDCS, said: "River dolphins are amongst the most endangered of all whale and dolphin species. The pressures on them are immense, as was highlighted by the recent news of the extinction of the baiji in Asia. Urgent action is needed if we are to prevent Amazon River dolphins from suffering the same fate."
The river dolphin is coming increasing pressure from unsustainable fisheries, damming, deforestation, pollution, increased shipping and gold mining. Fishermen also catch and kill up to 1,500 dolphins annually for use as bait.
Trujillo completed the first ever survey of river dolphins left in the Orinoco and Amazon River basins and in seven expeditions in five countries, 3,188 dolphins were sighted.
The survey forms the basis of a conservation plan and 18 researchers across South America have been recruited and trained as part of the region's first network of dolphin scientists.
Trujillo said: "The meeting in Bolivia is a crucial step forward in the conservation and protection of one of the world's last remaining river dolphin species, helping to reverse the decline of these highly vulnerable species globally."