Posterior view of the Zhoukoudian Homo erectus (A) and the Xuchang 1 (B) cranium. Black arrow showing a low widest point of the vault; Blue arrow showing a short and inward sloping mastoid process ...

Examples of cranial trauma. Top) perimortem injury to the left posterior of the frontal bone (a), cutmarks can also be seen on the frontal bone (b) and patinated bevel of the internal cranial surface ...

Also the skull bones or cranium grows along with the brain. This happens as the suture lines increase. By the age of two the baby’s skull would have achieved two third of its adult size.