Opposing thumb primates

In physical anthropology, many hold one of the ways man came to be what they are today is the dexterity of the opposing thumb. Some say it is the distinct advantage. They point to other primates that do not have the same exact thumb opposing position and even assume it is unique to humans.

They need to study closer. Looking directly at the adult Mandrill (and some lemurs), they have the same opposing thumb as humans and use it the same way for picking and grasping and carrying with more ease than other primates. The genders also share chores, e,g, males build the nest. Mandrills are very underrated.

There are other primates who also have dexterous opposing thumbs, e.g. baboons etc. but most use the thumb for scooping not plucking. Most arboreal species have such and a few land mammals, e.g. most marsupials.