Chimps Used Stone “Hammers”

Posted on February 14, 2007 5 Comments

Ancient chimp-made ‘hammers’ fuel evolutionary debate:

The stone hammers that the team discovered, essentially irregularly shaped rocks about the size of cantaloupes – with distinctive patterns of wear – were used to crack the shells of nuts. The research demonstrates conclusively that the artifacts couldn’t have been the result of natural erosion or used by humans. The stones are too large for humans to use easily and they also have the starch residue from several nuts known to be staples in the chimpanzee diet, but not the human diet.

Using so-called “percussive technology” to free the edible parts of nuts is more complicated than it sounds. “We know that modern chimpanzee behaviour regarding nut-cracking is socially transmitted and takes up to seven years to learn,” Mercader says. “Some of the nuts require a compression force of more than a thousand kilograms to crack. And the idea is to crack the shell but not smash it – it’s not a simple technique.”

The discovery suggests that a ‘chimpanzee stone age’ reaches well back to ancient times. “Chimpanzee material culture has a long prehistory whose deep roots are only beginning to be uncovered,” the authors write.

Related: Archaeologists Find Signs of Early Chimps’ Tool Use – Excavators say they’ve found tools made by chimps

5 thoughts on “Chimps Used Stone “Hammers””

  1. Pingback: Curious Cat Science and Engineering Blog » Capuchin Monkeys Using Stone Tools

  2. Raul Cancino

    Birds by entries of the parking lot street, one December day, I was by the window watching them the way how one of them trying in different ways to put a MacDonald bag upside down with the purpose to put out the staff, that bag has it, finally after 5 to 10 minutes, half hamburger and potato chip got out from the bag and spread out to the floor while the other two wanting for the feasting dinner. I painting them in a wood board with acrylic colors.

  4. Esther Boling

    Chimpanzees use stone hammer nuts, this finding is not surprising that also in survival evolution, they are very clever, I believe that there are many things we haven’t found.

  5. Pingback: Chimpanzees Use Spears to Hunt Bush Babies » Curious Cat Science and Engineering Blog

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