Researchers in Mexico had noticed what they believed were fossilized blood stains on stone knives as long as 20 years ago. But the institute said it took a methodical examination using a scanning electron microscope to positively identify the human tissues 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 at about the same time as the mysterious city-state of Teotihuacan. Cantona preceded by more than 1,000 years the region’s most famous human sacrifice practitioners, the Aztecs.
Story: Mark Stevenson, AP | Photo: Yadira Martinez, AP