Lesula

The Lesula is a remarkable new species of African monkey discovered in 2007 found in the Lomami Basin of the Congo. 

The monkey was seen (by non-locals) in 2007 by John and Terese hart of Yale University's Peabody Museum of Natural History, in the home of a primary school teacher in the town of Opala. 
The lesula is the second new species of African monkey to be discovered since 1984.^[1] This monkey is described to have human looking eyes and a blue bottom. “And adult males have a huge bare patch of skin in the buttocks, testicles and perianal area, “It’s a brilliant blue, really pretty spectacular," said John A. Hart. 

The species was listed among the Top 10 New Species out of more than 140 nominated species. The lesula lives in rainforests. 

The lesula is vulnerable to hunting for bushmeat. Protecting the species could be challenging, as species with such a small range can go from vulnerable to seriously endangered in a few years. The lesula's range is within the Tshuapa–Lomami–Lualaba Conservation Landscape, and the Lomami National Park has been proposed to protect this and other species in the region.