Outsize teeth of a black uakari from South America seem to indicate a meat diet and a fierce disposition, but in fact all uakaris are vegetarians and rather timid. Even when cornered, they rarely make use of their fangs. Lacking opposable thumbs, uakaris use these tusklike lower canines and long incisors as tools-they peel and tear fruit with them.
South America, Life Nature Library, 1964, Pg. 47.