Capuchin monkeys produce sharp stone flakes similar to tools

[Judi Lynn]

Capuchin monkeys produce sharp stone flakes similar to tools

Date: December 9, 2016

Source:Fundação de Amparo à Pesquisa do Estado de São Paulo

Summary:Researchers describe that rock fragments produced unintentionally today by primates in Serra da Capivara National Park in Brazil resemble tools made deliberately 2.6 million years ago by ancestors of humans.





In addition to using rocks for various purposes, such as cracking open a seed or fruit to extract the edible part, the Bearded or Black-Striped Capuchin (Sapajus libidinosus), a species of wild monkey found in Serra da Capivara National Park in Piauí State, Brazil, makes sharp stone flakes by strongly and repeatedly hammering one rock against another embedded in an outcrop with a clear intent to smash it. Monkeys observed performing this activity then lick and sniff the quartz dust resulting from the fragmentation of the rock.

This behavior by S. libidinosus frequently produces sharp-edged conchoidal flakes with smooth rounded facets resembling the shape of a scallop shell. The flakes resulting from multiple percussions are left where they fall and are not used as tools by the monkeys.

Researchers at the University of São Paulo's Psychology Institute (IP-USP) in Brazil, in collaboration with colleagues at the University of Oxford's Archeology School and University College London's Archeology Institute in the UK, analyzed the flakes inadvertently produced by S. libidinosus and found many that were similar to the lithic tools carved from rocks by hominins (human ancestors) during the Paleolithic era.

The research was conducted as part of the Thematic Project "Tool use by wild bearded capuchin monkeys (Sapajus libidinosus)," for which Eduardo Ottoni is principal investigator. The findings were published in the online version of the journal Nature.

More:
https://www.sciencedaily.com/releases/2016/12/161209184859.htm


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1. But are apparently not used as tools by the monkeys.

I wonder why they do that activity.

Interesting.

R&K

[Judi Lynn]

2. I think they use the big stones to chip away at the small stones, make them narrow, thin, sharp.

Also, if you smack a rock just right, it can fracture into shards with sharp edges.

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