长臂猿和尼安德特人（穴居人）

合趾猿是长臂猿中体型最大的一种，学名Symphalangus syndactylus，资料如下：
Kings (and queens) of swing
“Hylobates” means “dweller in the trees” and the siamang certainly lives up to that description. The siamang is in the same scientific family as gibbons, and is well-suited for life in a forest’s treetops. Unlike great apes, siamangs do not build nests because they sleep sitting upright on branches.
Their main way of traveling through the rain forest is by brachiation. The motion of their arms looks like the left-right motion of striding legs. During brachiation, the siamang hangs from a branch by one hand while swinging its body around to allow the other hand to grasp the next handhold. They are very acrobatic and agile. Their extra-long arms help them cover up to 10 feet (3 meters) in a single swing. If they’re not swinging through the trees, they’re very likely walking along branches with their arms outstretched to help them keep their balance.
Hands and feet
Siamangs’ hands are