Skull shaping is a thing that early cultures practiced. Along with foot binding and other mutilations that adults would practice on children.
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Artificial_cranial_deformation
Foot binding
Comprachicos
Yes, it's a documented practice, but it was only performed on infants after birth. The subject of the article was a fetus when it died, and its skull was already elongated.
As a side note, many of the elongated skulls that have been discovered, show none of the typical signs of cradle boarding, or intentional deformation.
Even stranger, a lot of them:
· Are missing the sagittal suture
· Have eye sockets much larger than normal humans
· Have larger than normal cranial capacity