Twenty-five of the world's most endangered species including several types of apes, monkeys and lemurs, have been identified at a UN conference on biological diversity in India, reports Reuters.
The endangered species are the closest living relatives to humans and are spread across Asia, Africa and South America.
According to the study, the world's most endangered primate species include Red Ruffed Lemur, Rondo dwarf galago, Madame Berthe’s Mouse Lemur, Roloway monkey, and Grauer’s gorilla.
Many of the primate's populations, from the Ecuadorian brown-headed spider monkey to the eastern black-crested gibbon in China and Vietnam, have been falling rapidly from deforestation, hunting and poaching.
One of the most critically endangered groups was the northern sportive lemur, which lives in Madagascar. AP reports that only 19 known individuals live in the wild.
"Lemurs are now one of the world's most endangered groups of mammals, after more than three years of political crisis and a lack of effective enforcement in their home country, Madagascar," Christoph Schwitzer of the Bristol Conservation and Science Foundation, one of the groups involved in the study, told AP.
"A similar crisis is happening in Southeast Asia, where trade in wildlife is bringing many primates very close to extinction," Schwitzer said.
Survival of these primates is critical for maintaining biodiversity.
Primates "often serve as seed dispersers and help to maintain forest diversity", Russell Mittermeier, a chair of the primate specialist group at the IUCN and president of Conservation International, told Reuters.
"It is increasingly being recognized that forests make a major contribution in terms of ecosystem services for people, providing drinking water, food and medicines," he wrote.
According to the International Business Times, there was a glimmer of hope. No primate species have been lost to extinction so far in the 20th and 21st centuries.