Gruesome evidence of funerary rituals that involved mutilation, removal of muscles and teeth, and possibly cannibalism of fresh corpses has been uncovered in Brazil, according to an international team of researchers.

Unearthed at Lapa do Santo, a cave in east-central Brazil, the 9,500-year-old remains provide the oldest documentation of humans performing complex funerary rituals in the region.

"In the absence of monumental architecture or grave goods, parts of fresh corpses were used in elaborate rituals," André Strauss, at the Erberhard-Karls Universität in Tübingen, Germany, said.

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Starting between 10,000 and 10,600 years ago, Lapa do Santo was used as a place of burial of complete bodies. Between 9,400 and 9,600 years ago more complex funerary rituals took place, featuring what Strauss and colleagues call "manipulation" and "reduction" of the corpses.

Such techniques included "mutilation, defleshing, tooth removal, exposure to fire and possibly cannibalism," the researchers wrote in the journal Antiquity.