Secrets of the blood knives
Blood cells and fragments of muscle, tendon, skin and hair on 2,000-year-old stone knives have been found in Mexico. Researchers called it the first conclusive evid-ence from a large number of stone implements pointing to their use in human sacrifice.
Mexico’s National Institute of Anthropology and History said the finding clearly corroborates accounts from later cultures about the use of sharp obsidian knives in sacrificing humans.
Other physical evidence such as cut marks on the bones of ancient human skeletons had previously offered indirect proof of the practice. Researchers in Mexico had noticed what they believed were fossilised blood stains on stone knives as long as 20 years ago.
But the institute said it was only after a methodical examination using a scanning electron microscope that human tissues were positively identified on 31 knives from the Cantona site in the central Mexico state of Puebla.
The collection of stone knives is from the little-known Cantona culture, which flourished just after the mysterious city-state of Teotihuacan. Cantona preceded by more than 1,000 years the region’s most famous human sacrifice practitioners, the Aztecs.
The archaeologists who found the knives gave them to researcher Luisa Mainou at the anthropology institute’s restoration laboratories about two years ago.
With help from specialists at Mexico’s National Autonomous University, they were studied under the scanning electronic microscope and found to contain red blood cells, collagen, tendon and muscle fibre fragments.
While historical accounts from Aztec times, as well as drawings and paintings from earlier cultures, had long suggested that priests used knives and other instruments for non-life-threatening bloodletting rituals, the presence of the muscle and tendon traces indicates the cuts were deep and intended to sever portions of the victim’s body.
“These finds confirm that the knives were used for sacrifices,” Ms Mainou said.
Susan Gillespie, associate professor of anthropology at the University of Florida who was not involved in the research project, said it was the first time to her knowledge that such tissue remains had been identified on obsidian knives.
She said other studies have found trace elements of organic remains such as food on ancient artefacts, so “with the right conditions such remains can preserve for long periods”.
Ms Gillespie said human sacrifice practices either described by the Spanish conquerors or depicted in pre-conquest paintings include heart removal, decapit-ation, dismemberment, disembowelling and skinning of victims.
Interestingly, the find announced has already begun to shed some new light on the murky sacrifice practices of pre-Hispanic cultures, which believed that human blood was a sort of vital liquid needed to keep the cosmos in peerfect balance.
For example, some knives had more traces of red blood cells while others had more skin and others more muscle or collagen, “which suggest that each cutting tool was used for a different purpose,”Ms Mainou said.
Ms Gillespie said the find also suggested the intriguing possibility that the sacrificial knives were ritually deposited, unwashed, in some special site after being used.
“The archaeological confirm-ation of human sacrifice is import-ant both for supporting or contesting the many post-conquest historical accounts and pre-conquest imagery of sacrifice,” Ms Gillespie wrote.