Smallest primates discovered in Madagascar

Lemurs are very primitive primates

Three previously unknown species of mouse lemur, the world's smallest primate, have been discovered in Madagascar.

It's incredibly rare to discover a new species of primate, let alone three new species

Steven Goodman, Field Museum

Their identification was made during a scientific survey of the island's western forests and later confirmed by genetic tests.

Lemurs are primitive primates that live in trees and are found only on the island of Madagascar and the nearby Comoro Islands off the east coast of Africa.

Mouse lemurs have heads that are no bigger than a human thumb and weigh just a few ounces (one ounce is 30 grams). Many of the animals, which have long noses, agile limbs, and piercing round eyes, are endangered because their forest habitat is being destroyed.

Island collection

An international research team compared the physical characteristics of mouse lemurs - their teeth, skulls, length, and body size - from 12 geographic locations.

Their newness to science was confirmed by genetic tests

The scientists' survey found seven different mouse lemur species, including three new to science. "It's incredibly rare to discover a new species of primate, let alone three new species," said Steven Goodman, of the Field Museum of Natural History in Chicago, who participated in the study.

Madagascar's forests are home to an amazing variety of unique plant and animal life, including probably more than 12,000 species of flowering plants, 300 species of butterflies, and nearly 100 species of mammals.

Nearly 100% of the mammals on the island are endemic, which means they exist only there and nowhere else on Earth.

'Slash and burn'

Scientists believe Madagascar split off from the continent of Africa about 165 million years ago making the island a significant site for the study of evolutionary biology.

Lemurs are particularly important because they are the most primitive of living primates. Some of their fossils date back about 58 million years.

"Understanding aspects of lemur biology and evolution gives us a window into the history of more advanced primates, like ourselves," said Rodin Rasoloarison, of the University of Antananarivo in Madagascar and the Deutsches Primatenzentrum in Germany, who participated in the survey.

However, many animal species, not just the lemurs, may struggle to survive on Madagascar in the future. The island has already been stripped of 90% of its original forests and traditional "slash and burn" agriculture continues to eat into the remaining habitats.

The three new species of mouse lemur are Microcebus berthae, Microcebus sambiranensis, and Microcebus tavaratra. Their discovery is reported in the December edition of the International Journal of Primatology.