Image credit: Noel Rowe; Maurice Emetshu/ Public Library of Science/AP Photo

NAIRPOBI, Kenya - The world's newest-known monkey is a shy creature with bright-blue buttocks that lives quietly in the remote rain forests of central Africa, according to the American researchers who discovered a new monkey species.

Cercopithecus Lomamiensis, locally called the lesula, is barefaced and has a long nose and an aquamarine backside. It is well-known to hunters in the Lomami forest basin in the Democratic Republic of the Congo, but researchers said the area has had little biological exploration and the species was unknown to those outside the region.

Lead researcher John Hart of Yale University's Peabody Museum of Natural History and the Lukuru Wildlife Research Foundation was not in the wild when he first spotted the curious monkey in 2007. He was fanning through photographs brought back from the field and noticed something unusual about a young female monkey being kept in a village as a 13-year-old girl's pet.

"When I first saw it, I immediately knew it was something new and different. I just didn't know how significant it was," Hart told "OurAnimalPlanet."

Hart and fellow researchers spent the next five years doing field, genetic and anatomical research to find out more about the mysterious monkey. Their discovery was made known to the world this week when they published their research in the open-access PLoS ONE journal.

Hart calls the lesula, which has a blond mane and bright-red patch on its lower back, a "gorgeous" animal Male lesulas can weigh up to 15 pounds, twice that of female lesulas. Males also have bright blue buttocks, which stand out in the dark, dense rain forest they roam.

Researchers hope the discovery of the lesula will lead to its protection. While it is not considered an endangered species, Hart says it is vulnerable because of the high demand for bush meat in the relatively small area it inhabits.