Final answer:
Bipedalism is the trait unique to hominins and not found in other primates; primates generally have binocular vision, grasping hands, and fingernails.
Step-by-step explanation:
The trait unique to hominins and not found in other primates is bipedalism. While many primates have adaptations for climbing and some for brachiation, only hominins are adapted for walking on two feet as their primary mode of locomotion. Other primates may walk on two legs occasionally, but they do not have the hip structure that supports consistent and efficient bipedal walking as seen in hominins. Primates generally do have binocular vision, grasping hands with opposable thumbs, and fingernails instead of claws, so these traits are not unique to hominins.