Primate

Primates are one of the 18 mammal orders, distinguished by:

- frontal eyes used for binocular vision, matched with significant development of visual areas in the brain;

- limbs with 5 digits, with flat nails on the ends;

- prehensile hands with opposable thumbs.

Primates appeared at the end of the Secondary Era, about 70 million years ago. It was not until the late Tertiary Era that primates walked upright.