The primate is a type of slow loris, a small cute-looking animal that is more closely related to bushbabies and lemurs than to monkeys or apes.
Uniquely among primates, they have a toxic bite, belying their appearance.
Two previously known subspecies of slow loris have also been accorded full species status.
Details of the discoveries are published in the American Journal of Primatology.
The new species of slow loris, named Nycticebus kayan, has gone unrecognised until now, in part due to its nocturnal lifestyle.
Animals that are active by night often rely less on visual clues, and can therefore appear more similar to one another.
So the scientists had to look hard to discover the differences between the new species.
source : http://www.bbc.co.uk/nature/20704172