southern muriqui

The southern muriqui (Brachyteles arachnoides) is a critically endangered primate found only in the Atlantic forests of southeastern Brazil. It is the largest monkey in South America and is characterized by its thick fur, heavy body, and long limbs, with reduced thumbs.1

There are two species of woolly spider monkeys: the southern muriqui, which has a black face and no thumb, and the northern muriqui (B. hypoxanthus), which has a mottled pink and black face and a rudimentary thumb. Both species are diurnal, arboreal, and feed on leaves, seeds, and fruit, often hanging by their prehensile tails. They live in small, flexible social groups.1