Archeologists working on a dig in Chincha Valley, Peru have found nearly 200 human spines threaded onto reed posts dating from the end of the Incan Empire and the beginning of European colonization from 1450 to 1650 AD.

The finds are detailed in the April 2022 edition of the journal Antiquity, where researchers posit that the remains are from a social aspect of the civilization as a way to “reconstruct” their dead after Colonial-period looting of graves. This treatment of human remains has never been documented in the region before.

The discoveries were made by an international team of archeologists on the southern coast of Peru, most of which were in large, elaborate Indigenous graves known as “chullpas,” hundreds of which are scattered in the region.

The team found 192 vertebrae on posts in the region of their dig, each post appears to contain the remains of single individuals, both adult and juvenile.

“This was a turbulent period in the history of the Chincha Valley, when epidemics and famines decimated local peoples,” said lead author Jacob L. Bongers in a release.

The Chincha Valley had been the site of the Chincha Kingdom from 1000 to 1400 AD, which established an alliance with the Inca Empire and was eventually consolidated into it, the study says.

However, the arrival of the Europeans “devastated” the region and the population declined “catastrophically” from more than 30,000 heads of households in 1533 to 979 in 1583.

“Looting of Indigenous graves was widespread across the Chincha Valley in the Colonial period,” according to Bongers, who has previously researched grave looting in the region. “Looting was primarily intended to remove grave goods made of gold and silver and would have gone hand-in-hand with European efforts to eradicate Indigenous religious practices and funerary customs.”

The study posits that putting the vertebrae on posts may have been a way to repair the damage done by looting, as radiocarbon dating suggests it was done after the initial burial. Researchers believe the Indigenous people were returning to the chullpas to reconstruct their dead.

“These “vertebrae-on-posts” were likely made to reconstruct the dead in response to grave looting,” Bongers said. “Our findings suggest that vertebrae-on-posts represent a direct, ritualized, and Indigenous response to European colonialism.”

Many Indigenous groups in the region had social customs that placed bodily integrity after death as integral to death rituals. The nearby Chinchorro people developed the first known techniques for artificial mummification, the study says, millennia before ancient Egypt.

When mummies in the Andes were destroyed by Europeans, the Indigenous people salvaged what they could to make new ritual objects, which researchers believe the spines on reed rods they found followed in that vein.

“Ritual plays important roles in social and religious life, yet can become contested, especially during periods of conquest in which new power relationships become established,” said Bongers. “These finds reinforce how graves are one area where this conflict plays out.”