New river dolphin species discovered

Scientists in Brazil have identified the first new species of river dolphin in almost 100 years.

Considered to be some of the world's rarest animals, river dolphins can be found in a small number of rivers and estuaries across South America and Asia.

Up until now only four known species of river dolphin had ever been identified, but researchers working in Brazil believe that they've discovered a fifth species, one that lives in the Araguaia river basin.

With a population of fewer than 1,000 individuals, the new species is believed to have been separated from the Amazon river dolphin around two million years ago and shares many of the same traits.

Conservationists are worried however that the animals are already at risk and could soon disappear if efforts are not made to protect them