@article {331219,
	title = {Flake production: A universal by-product of primate stone percussion},
	journal = {Proceedings of the National Academy of Sciences },
	volume = {122},
	year = {2025},
	note = {<p>doi: 10.1073/pnas.2420067122</p>
},
	month = {2025/02/18},
	pages = {e2420067122},
	abstract = {<p>An important avenue for understanding the origins of early hominin technology is the stone tool record of contemporary primate populations. Our research focuses on the stone tool record of yellow breasted capuchins (Sapajus xanthosternos) from Fazenda Matos in Brazil. We show that this species, through habitual nut-cracking activities produces a diverse fragmented lithic record, including the unintentional production of sharp-edged flakes, like those commonly associated with early hominin technology. By comparing this record across primate species, we show that flake production is a constant. This evidence highlights the potential importance of subsistence percussive behaviors as one of the possible mechanisms behind the emergence of hominin stone tool technology. The evolution of stone tool technology marks a significant milestone in hominin development, enabling early humans to manipulate their environments. The oldest known evidence, dating to 3.3 Ma, indicates a combination of percussive and flake production activities. Studying the archaeological signature of percussive stone tool use in living primate provides a potential analog to the origin of stone flake technology in the hominin lineage. Here, we present a yellow-breasted capuchin (Sapajus xanthosternos) stone tool assemblage from Fazenda Matos, Brazil, to explore the variability of the material signatures associated with percussive tool use. Our analysis of this record demonstrates many archaeological features previously associated with intentional flake production. This includes hammerstones with substantial percussive damage and a range of flaked and detached pieces. Comparative analyses with other flaked primate and hominin assemblages reveals that, unintentional flake production is a universal component of stone hammer and anvil percussive behaviors, suggesting that similar behaviors by early hominins may have led to stone flake technology and that this record may have been highly variable. To fully understand the origins of hominin stone technology, a broad spectrum of material records including both hominin and primate must be considered.An important avenue for understanding the origins of early hominin technology is the stone tool record of contemporary primate populations. Our research focuses on the stone tool record of yellow breasted capuchins (Sapajus xanthosternos) from Fazenda Matos in Brazil. We show that this species, through habitual nut-cracking activities produces a diverse fragmented lithic record, including the unintentional production of sharp-edged flakes, like those commonly associated with early hominin technology. By comparing this record across primate species, we show that flake production is a constant. This evidence highlights the potential importance of subsistence percussive behaviors as one of the possible mechanisms behind the emergence of hominin stone tool technology. The evolution of stone tool technology marks a significant milestone in hominin development, enabling early humans to manipulate their environments. The oldest known evidence, dating to 3.3 Ma, indicates a combination of percussive and flake production activities. Studying the archaeological signature of percussive stone tool use in living primate provides a potential analog to the origin of stone flake technology in the hominin lineage. Here, we present a yellow-breasted capuchin (Sapajus xanthosternos) stone tool assemblage from Fazenda Matos, Brazil, to explore the variability of the material signatures associated with percussive tool use. Our analysis of this record demonstrates many archaeological features previously associated with intentional flake production. This includes hammerstones with substantial percussive damage and a range of flaked and detached pieces. Comparative analyses with other flaked primate and hominin assemblages reveals that, unintentional flake production is a universal component of stone hammer and anvil percussive behaviors, suggesting that similar behaviors by early hominins may have led to stone flake technology and that this record may have been highly variable. To fully understand the origins of hominin stone technology, a broad spectrum of material records including both hominin and primate must be considered.</p>
},
	doi = {https://doi.org/10.1073/pnas.2420067122},
	url = {https://www.pnas.org/doi/10.1073/pnas.2420067122},
	author = {Proffitt, Tomos and de Sousa Medeiros, Paula and Martins, Waldney Pereira and Luncz, Lydia. V.}
}
