"Finding an entirely new species of lemur living in the wild in the 21st century shows how little we know about our natural world, and how important it is to protect it," said primatologist Mireya Mayor, who discovered one of the new trio while on an expedition in northeast Madagascar.

One of the new species is named Microcebus mittermeieri, or Mittermeier's mouse lemur, after Russell A. Mittermeier, the president of green group Conservation International and a renowned field primatologist.

"Other scientific discoveries come and go, but a new species becomes a permanent part of the scientific record, and will be with us forever," Mittermeier said.

Madagascar is home to over 70 species of lemurs, primitive primates which are distant relations to humanity. They have caught the public imagination in the wake of the animated DreamWorks film "Madagascar".

Lemurs are found only on Madagascar and some neighbouring islands and are endangered throughout much of their range on the huge island state, one of the world's poorest countries which has lost much of its forest to slash and burn agriculture.

The government has committed itself to tripling the amount of protected space to six million hectares as it attempts to establish itself as a destination for eco-tourists.

Mittermeier's mouse lemur resembles a small, reddish bundle of fluff with huge eyes as it is nocturnal.