Vanzolini’s bald-faced saki

The Vanzolini's bald-faced saki is a New World Monkey that lives in Western Brazil. It was assumed to be extinct until 2017, when it was rediscovered. Unlike other monkeys, it lacks a prehensile tail that allows it to easily swing through trees. Instead, they run on all fours across thin branches.

https://news.nationalgeographic.com/2017/08/saki-vanzolini-monkey-amazon-rainforest-video-spd/