Strange headpieces might have been protection for the souls of those who died young.

Scientists excavating ancient graves in South America have discovered an unprecedented garb for the dead: children’s skulls that were fashioned into helmets and placed over the heads of two smaller buried children.

The Salango archaeological site in western Ecuador includes two small burial mounds built in roughly 100 bc by people of the local Guangala culture. In one mound, Sara Juengst at the University of North Carolina at Charlotte and her colleagues found the bones of a 6- to 9-month-old baby whose head was encased in the skull of a child aged between 2 and 12. In the second mound, the team found an 18-month-old toddler wearing another such helmet from a child between 4 and 12 years of age.

In both cases, the wearer’s face was positioned to look out from what would have been the top of the source child’s skullcap. The helmets were probably affixed before burial and might have been intended to protect the souls of the children who wore them.