The Lesula, a new species of monkey discovered in the Democratic Republic of Congo by researchers Terese and John Hart and their team. (photo: Flickr/teresehart)

Meet lesula, a new species of monkey discovered in the Democratic Republic of Congo — just the second new species of monkey discovered in Africa in the past 28 years.

The husband and wife research team of Terese and John Hart first saw the moon-eyed monkey in June 2007, being kept as a pet.

Six months later, their searches of the region turned up the first lesula spotted in the wild.

They enlisted help from New York University geneticists and from morphologists at Yale University's Peabody Museum to conduct rigorous scientific testing. They had an audiologist record the animal's vocalizations for comparison, and conducted their own observations of the monkey's behaviour.

"Our conclusion: This is a new species of monkey," they write in their announcement, published this week in the scientific journal Plos One.  

Cercopithecus lomamiensis is described as "a medium sized, long-limbed monkey with a slender body." The Harts are certain lesula is a distinct species from the owl-faced monkey, which it resembles.

"Morphological and molecular data confirm that C. lomamiensis is distinct from its nearest congener, C. hamlyni, from which it is separated geographically by both the Congo (Lualaba) and the Lomami Rivers," they wrote.

The lnesula's range is at least 17,000 km of mostly unexplored forest. Even so, the scientists say the species is at risk due to bushmeat hunting, and "urgently" requires protection.

"For species with restricted ranges and reliance on primary forest, such as C. lomamiensis, uncontrolled hunting can lead to catastrophic declines over a short period."