Mexico: Glass Knives Used For Human Sacrifice

Archaeologists in Mexico say they have found conclusive evidence that knives were used in human sacrifice as long as 2,000 years ago.

They were speaking after blood cells and fragments of muscle, tendon, skin and hair were positively identified on knives made of obsidian, a volcanic glass.

The artefacts come from the little-known Cantona culture, which flourished just after the mysterious city-state of Teotihuacan.

Cantona was more than 1,000 years earlier than the region's most famous human sacrifice practitioners, the Aztecs.

Scientists from Mexico's National Institute of Anthropology and History had seen what they believed were fossilised bloodstains on stone knives as long as 20 years ago.

But it was only after a methodical examination using a scanning electron microscope that the human tissues on 31 knives from the Cantona site in the central Mexico state of Puebla could be positively identified.

Other physical evidence such as cut marks on the bones of ancient human skeletons had previously only offered indirect proof of the practice.

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.

But the presence of the muscle and tendon traces on the knives indicated the cuts were deep and intended to sever portions of the victim's body.

"These finds confirm that the knives were used for sacrifices," said researcher Luisa Mainou, who tested the knives.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."This is a compelling demonstration that these knives were used to cut human flesh," Professor Gillespie said.

"The archaeological confirmation of human sacrifice is important both for supporting or contesting the many post-conquest historical accounts and pre-conquest imagery of sacrifice."

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", she said.

Human sacrifice practices either described by the Spanish conquerors or depicted in pre-Conquest paintings include heart removal, decapitation, dismemberment, disembowelling and skinning of victims, she explained.