Final answer:
Primate skeletons differ from those of other mammals due to adaptations for arboreal living and advanced vision, such as hands and feet designed for climbing, stereoscopic vision, larger brain sizes, and a tendency towards upright posture.
Step-by-step explanation:
The primate skeletal structure is differentiated from that of other mammals in various ways, primarily as adaptations for their arboreal lifestyle and for advanced vision. Unlike other mammals, primates typically have hands and feet that are adapted for climbing and brachiation, with features such as a rotating shoulder joint, a big toe widely separated from the other toes (except in humans), and opposable thumbs that allow for gripping branches. Additionally, primates display stereoscopic vision, a result of having large, forward-facing eyes that provide overlapping visual fields, which is essential for depth perception. Another distinguishing feature is the size of their brains, which are larger relative to body size than those of most other mammals. Furthermore, most primates have flattened nails instead of claws, tend to have only one offspring per pregnancy, and their body structure favors an upright posture.