The black squirrel monkey (Saimiri vanzolinii), also known as the blackish squirrel monkey or black-headed squirrel monkey, is a small New World primate, endemic to the central Amazon in Brazil. It largely resembles the female of the far commoner Bolivian Squirrel Monkey, though the latter lacks the black central back.This squirrel monkey has one of the most restricted geographical distributions for a primate, living in várzea forest in the confluence of the Japura and Solimoes rivers.