(Cacajao calvus)
It is characterized by having all the face,forehead and upper part of the skull lacking hair and a red color that stands out and contrasts with the rest of the body,which has thick brown,grayish or whitish fur.The face is wide and the nostrils are widely separated.3 Weighs between 2.75 and 3.45 kg,while the length of the body and head in the males averages 45.6 cm and 44 cm in the females.4 The tail is short between the platirrinos,not prehensile and measures on average only 15 cm,less than half the body length.5 The fangs are well developed to open thick shells.