Since macadamias are originally from Australia, I wrote to an
Australian company that sells them, to find out whether
Australians aborigines might have been able to use them as a
food source.  I was told that they can be cracked open with two
heavy stones.

This is another example of a food that could have been eaten by
paleolithic humans but which only a small isolated population had
access to until very recently.

Todd Moody
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