Chimpanzee's are a member of the primate family, and one of the closest relatives to humans. The Chimpanzee differs from a human however in a number of ways.
One such way is the number of bones located in the skull. In Chimpanzees and other primates, there are 28 bones located in the skull, while humans only have 22. Chimpanzee skulls, despite having more bones, have a much smaller skull volume, about 1/3rd as large when compared to humans. Because of this smaller skull volume, the brain of the chimpanzee is also relatively smaller than that of a human.
Interestingly, a number of bones that account for the 28 found in the chimpanzee skull are very small. For example, the bones involved in hearing are some of the smallest found in the entire body. Hope this helps!