Archaeologists in Salango, Ecuador, recently uncovered two infant skeletons buried with "helmets" made from the skulls of older children, Gizmodo reports.

The discovery is the first of its kind, researchers write in a paper published in the journal Latin American Antiquity. To date, the Salango discovery presents the only known evidence of ancient people using juvenile skulls as burial headgear.

The two burial mounds where the skeletons were uncovered date back to about 100 BCE. It's likely that the skull "helmets" were cut and fitted to the infants' heads while the former were "still fleshed," the researchers write. One infant, estimated to be about 18 months old at the time of death, wears the skull of a child between 4 and 12 years old. The “helmet” was positioned so that the wearer looked “through and out of the cranial vault,” the paper reports (the cranial vault is the area of the skull where the brain is stored). The second infant, which was between 6 and 9 months old at death, is fitted with the skull of a child between 2 and 12 years old.

© Sara Juengst

But why? The archaeologists involved in the discovery aren’t totally sure. Ash found near the burial site suggests that a volcano may have impeded agriculture, leading to malnourishment and starvation. The skull helmets could have been an effort to offer the infants additional protection beyond the grave. It’s also possible, though unlikely, that the children could have been sacrificed in a ritual to protect the community from natural disasters. That’s less probable, though; none of the bones show any evidence of trauma, but they did show signs of anemia, suggesting that all four children were sick at their time of death. Researchers hope DNA and isotope analyses can offer more information on the discovery.

Whatever the reason is, it’s important not to judge with modern eyes, lead author Sara Juengst told Gizmodo. “Our conception of death is based in our modern medical, religious, and philosophical views,” she said. “We need to think about things in their own context as much as possible and try to keep our own prejudices or ideas about 'right/wrong' out of the analysis.”

[h/t Gizmodo]