More than 2000 years ago dead babies in South America were buried wearing the skulls of older children like they were helmets.
Archaeologists in Ecuador dug up the remains between 2014 and 2016, but have only just revealed the horrifying find to the world.
"At Salango, a ritual complex on the central coast of Ecuador, excavations revealed two burial mounds dated to approximately 100BC," researchers wrote in journal Latin American Antiquity.
"Among the 11 identified burials, two infants were interred with 'helmets' made from the cranial vaults of other juveniles."
They say it's the first time anything like it has ever been found in the world.
University of North Carolina assistant professor Sara Juengst, who led the study, told sci-tech news site Gizmodo they were "pretty surprised" when they realised what they had.
The 'helmets' were provided by kids between four and 12 years old, and were "still fleshed". Their bodies weren't found.
A hand bone was also found between one of the babies' heads and their helmet.
"For modern people who are horrified by these findings, I would remind them that our conception of death is based in our modern medical, religious, and philosophical views," said Juengst.
" While we are usually averse to handling dead bodies, there is a lot of precedent around the world of cultures who don’t have this aversion."
Her belief is the helmets were intended to provide protection for the infants in the afterlife. It's not known how they died, but the burial appears to have taken place soon after a volcanic eruption and there's evidence they were suffering malnutrition.
Ecuador was inhabited by a range of peoples in the centuries before the arrival of the Incas, with the burial site believed to contain bodies of Guangala people.
