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Our understanding of the emergence of technology shapes how we view the origins of humanity. Sharp-edged stone flakes, struck from larger cores, are the primary evidence for the earliest stone technology. Here we show that wild bearded capuchin monkeys (Sapajus libidinosus) in Brazil deliberately break stones, unintentionally producing recurrent, conchoidally fractured, sharp-edged flakes and cores that have the characteristics and morphology of intentionally produced hominin tools. The production of archaeologically visible cores and flakes is therefore no longer unique to the human lineage, providing a comparative perspective on the emergence of lithic technology. This discovery adds an additional dimension to interpretations of the human Palaeolithic record, the possible function of early stone tools, and the cognitive requirements for the emergence of stone flaking.
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00 MONTH 2016 | VOL 000 | NATURE | 1
LETTER doi:10.1038/nature20112
Wild monkeys flake stone tools
Tomos Proffitt1*, Lydia V. Luncz1*, Tiago Falótico2, Eduardo B. Ottoni2, Ignacio de la Torre3 & Michael Haslam1
Our understanding of the emergence of technology shapes how
we view the origins of humanity1,2. Sharp-edged stone flakes,
struck from larger cores, are the primary evidence for the earliest
stone technology3. Here we show that wild bearded capuchin
monkeys (Sapajus libidinosus) in Brazil deliberately break stones,
unintentionally producing recurrent, conchoidally fractured,
sharp-edged flakes and cores that have the characteristics and
morphology of intentionally produced hominin tools. The
production of archaeologically visible cores and flakes is therefore
no longer unique to the human lineage, providing a comparative
perspective on the emergence of lithic technology. This discovery
adds an additional dimension to interpretations of the human
Palaeolithic record, the possible function of early stone tools,
and the cognitive requirements for the emergence of stone
Palaeoanthropologists use the distinctive characteristics of flaked
stone tools both to distinguish them from naturally broken stones
and to interpret the behaviour of the hominins that produced them4.
Suggested hallmarks of the earliest stone tool technology include
(i) controlled, conchoidal flaking5;(ii) production of sharp cutting
edges6; (iii) repeated removal of multiple flakes from a single core;
(iv) clear targeting of core edges; and (v) adoption of specific flaking
patterns7. These characteristics underlie the identification of intentional
stone flaking at all early archaeological sites3,5,7–12, as they do not
co-occur under natural geological conditions.
To date, comparisons between hominin intentional stone flaking
and wild primate stone tool use have focused on West African
chimpanzees (Pan troglodytes verus)
. Nevertheless, stone breakage
during chimpanzee tool use is accidental
, a result of missed hits or
indirect force application during activities such as nut-cracking. The
resulting stone fragments lack most of the diagnostic criteria listed
above for hominin flakes10,17. Even when the manufacture of sharp
edges was taught to captive bonobos (Pan paniscus), the resulting flaked
assemblage did not replicate the early hominin archaeological record
The capuchins of Serra da Capivara National Park (SCNP) in Brazil
use stone tools in more varied activities than any other known non-
human primate, including for pounding foods, digging and in sexual
displays19–21. Bearded capuchins and some Japanese macaques (Macaca
fuscata) are known to pound stones directly against each other22, but
the SCNP capuchins are the only wild primates that do so for the
purpose of damaging those stones
. This activity, which we term stone
on stone (SoS) percussion, typically involves an individual selecting
rounded quartzite cobbles from a conglomerate bed (active hammers),
and with one or two hands striking the hammer-stone forcefully and
repeatedly on quartzite cobbles embedded within the conglomerate
(passive hammers) (Fig. 1, Supplementary Video 1).
Previous observations of capuchin stone percussion indicate that
this behaviour occurs in an aggressive context23. In our observations,
however, the monkeys licked or sniffed the crushed passive hammers
in about half of the SoS percussion events19 (Supplementary Video 1),
suggesting that they may be ingesting either powdered quartz or lichens.
While the stones do not contain any biologically active components19,
silicon is known to be an essential trace nutrient24. SCNP capuchins
have also been seen to use a stone hammer to dislodge another stone
from the conglomerate, with the second stone then used as a hammer
for SoS percussion20.
As well as deliberately crushing the surface of both the active and
passive hammers, the capuchins regularly unintentionally fracture the
stones during use (Supplementary Video 1). In addition, we observed
a capuchin place a newly fractured stone flake on top of another stone,
and then strike it with a hammer in a manner resembling chimpanzee
nut-cracking or human bipolar reduction (Supplementary Video 1).
Nevertheless, while the monkeys were seen to re-use broken
hammer-stone parts as fresh hammers, they were not observed using
the sharp edges of fractured tools to cut or scrape other objects.
We collected fragmented stones immediately after capuchins
were observed using them at the Oitenta site in SCNP (8° 52.394 S,
42° 37.971 W) (Fig. 1), as well as from surface surveys and archaeolo-
gical excavation in the same area (Extended Data Fig. 1). The assemblage
consists of 111 capuchin-modified stone artefacts, including complete
1Primate Archaeology Research Group, School of Archaeology, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford OX1 3QY, UK. 2Institute of Psychology, University of São
Paulo, São Paulo, SP 05508-030, Brazil. 3Institute of Archaeology, University College London, 31–34 Gordon Square, London WC1H 0PY, UK.
*These authors contributed equally to this work.
Figure 1 | Wild bearded capuchin SoS percussion, Serra da Capivara
National Park, Brazil. a, The conglomerate outcrop where SoS percussive
behaviour of b and c was observed. b, c, SoS percussive actions including
close observation by a juvenile capuchin (b), and stone breakage (c).
Note that the active hammer in use is part of Refit Set 6 (Supplementary
Information and Supplementary Video 1).
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
2 | NATURE | VOL 000 | 00 MONTH 2016
and broken hammer-stones, complete and fragmented flakes, and
passive hammers. We also found flaked hammer-stones, which using
a traditional classification would be considered flaked artefacts25
(Extended Data Table 1). All stones were originally obtained by the
capuchins from conglomerates in the vicinity of their use.
Complete hammer-stones have a mean weight of 600.3 g (Extended
Data Table 2a). They possess varying degrees of percussive damage
across their surfaces, including small impact points surrounded by
circular or crescent scars (Supplementary Information and Extended
Data Fig. 2). Broken hammer-stones and flaked hammer-stones
comprise over a quarter of the total assemblage. Broken hammer-stones
are on average smaller than complete hammer-stones (mean = 203.8 g;
Extended Data Table 2a), and some would be termed split cobbles in
a hominin assemblage. Flaked hammer-stones exhibit one or more
conchoidal or wedge flake scars, occurring either as 1–2 fortuitous
scars from a natural striking platform, or as recurring unidirectional,
overlapping flakes resulting from repeated strikes on a fracture plane
(Fig. 2, Supplementary Information and Extended Data Fig. 3). Refitted
hammer-stones demonstrate this reduction sequence (Supplementary
Information and Extended Data Figs 4, 5). Continuous rotation and
manipulation of the hammer-stones during use also produces small
(< 1 cm), non-invasive, step-terminating flake scars along the edge
of the striking platform, perpendicular to the flaking surface. These
artefacts are indistinguishable from some archaeological examples
of intentionally flaked early hominin stone cores. Using a traditional
classification, the flaked hammer-stones fall within the morphology
of unifacial choppers1.
Complete flakes produced during SoS percussion have sharp edges,
bulbs of percussion and scars from up to three previous flake removals
(Fig. 2, Supplementary Information and Extended Data Fig. 6).
A high proportion of wedge-initiated flakes occur in the early
stages of reduction, evidenced by an increased frequency of cortical
Figure 2 | Examples of flaked stones from capuchin SoS percussion.
a, Detail of a large, unidirectionally flaked active hammer-stone, with
clear impact marks located towards the centre of the striking platform.
b, Refitted active hammer illustrating recurrent unidirectional removal of
at least seven flakes (Refit Set 6; Extended Data Fig. 6b and Supplementary
Video 2). c, e, Examples of conchoidal flakes. Artefact illustrations in e
reproduced with permission from A. Theodoropoulou. d, f, Examples of
flaked hammer-stones. af, Scale bars are 5 cm, except for the scale bar in
the inset (a), which is 2 mm.
2 mm
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00 MONTH 2016 | VOL 000 | NATURE | 3
flakes. Conchoidal flakes, on the other hand, come from both early
and later stages of reduction, with both cortical and non- cortical
pieces represented. Extensive refits record the production of unidi-
rectional recurrent, conchoidal flakes following an initial forceful
fracture (Extended Data Figs 5, 6, Supplementary Information and
Supplementary Video 2).
Passive hammers, whether found detached from or embedded in
the conglomerate, typically have a localized area of percussive damage
located on a prominent surface (Fig. 3). The damage includes impact
points, battering marks and crushed quartz crystals and, in some
cases, detached flakes or chips. The passive hammers in this study
(mean = 303.7 g, Extended Data Table 2a) also retain evidence of their
subsequent re-use as active hammers, with impact points located on
previously embedded flat planes opposite the passive hammer damage.
This use clearly occurred after the stone was dislodged from the
conglomerate. Capuchin SoS tools are therefore multifunctional,
with the monkeys able to repurpose stones from a passive to an active
percussive role (Supplementary Information).
The distinctive assemblages found at SoS percussion sites will guide
future archaeological investigations into the development of capuchin
technology at SCNP26, and the broader Middle Pleistocene dispersal of
Sapajus into northeast Brazil
. They should also assist in distinguishing
human tools from capuchin artefacts where the ranges of these primates
overlap12. Of interest beyond Sapajus behavioural evolution, SCNP
capuchins produce stone debris through a similar technique (passive
hammer) to that inferred from some of the earliest hominin archae-
ological assemblages3,11. The passive hammer knapping technique
involves striking a hammer-stone onto a passive anvil, with the desired
flakes detached from the hand-held stone
(Supplementary Video 1).
Both active and passive hominin hammers often have repeated
impact marks away from the tool’s edge, interpreted as evidence of
poorly controlled strikes or multi-purpose tool use
. SCNP capuchin
behaviour demonstrates that these marks and recurrent conchoidally
fractured, sharp-edged flakes, can be produced entirely unintentionally.
The SCNP data provide an example of repeated conchoidal flaking
that is not reliant on advanced, human-like hand morphologies and
coordination28. Similarly, SoS behaviour presents an alternative to
evolutionary explanations that link the origins of recurrent flake
production to a change in hominin cognitive skills28,29. In the absence
of supporting evidence such as cut-marked bones, we suggest that
sharp-edged flake production can no longer be implicitly or solely
associated with intentional production of cutting flakes. Capuchin
SoS percussion and simple Pliocene–Pleistocene stone knapping
activities are equifinal behaviours in the production of flaked lithic
assemblages. These findings open up the possibility that unintentional
flaked assemblages may be identified in the palaeontological record of
extinct apes and monkeys. In light of this possibility, criteria commonly
used to distinguish intentional hominin lithic assemblages need to
be refined.
No living primate is a direct substitute for extinct hominins,
which varied in unknown ways from the behaviour, cognition and
morphology seen in extant animals and humans15. However, capuchin
SoS percussion is an example of intentional stone breakage by a
non-human primate that produces concentrated lithic accumulations.
Capuchin SoS percussion flakes and flaked hammer-stones fall within
the range of mean dimensions for simple flakes and cores from the
Early Stone Age3 (Supplementary Information and Extended Data
Table 2b). If encountered in a hominin archaeological context, this
material would be identified as artefactual, potentially interpreted as
the result of intentional stone fracture and controlled flake production,
and probably attributed to functional needs requiring the use of
sharp edges.
The capuchin data add support to an ongoing paradigm shift in our
understanding of stone tool production and the uniqueness of hominin
technology. Within the last decade, studies have shown that the use
and intentional production
of sharp-edged flakes is not necessarily
tied to the genus Homo. Capuchin SoS percussion goes a step further,
demonstrating that the production of archaeologically identifiable
flakes and cores, as currently defined, is no longer unique to the human
Online Content Methods, along with any additional Extended Data display items and
Source Data, are available in the online version of the paper; references unique to
these sections appear only in the online paper.
Received 15 June; accepted 21 September 2016.
Published online 19 October 2016.
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Supplementary Information is available in the online version of the paper.
Acknowledgements The study was funded by a European Research
Council Starting Investigator Grant (#283959) to M.H. and São Paulo
Research Foundation (FAPESP) awards to T.F. (#2013/05219-0) and E.B.O.
(#2014/04818-0). Support for fieldwork and analysis was provided by
N. Guidon and G. Daltrini Felice of FUMDHAM and University College London
(ERC Starting Grant #283366). We thank R. Fonseca de Oliveira for excavation
coordination, M. Gumert, R. Mora and A. Arroyo for comments, and
A. Theodoropoulou for artefact illustrations. Fieldwork at SCNP was
approved by Brazilian environmental protection agencies (IBAMA/ICMBio
Author Contributions M.H. and T.F. observed and recorded the capuchin
behaviour, collected lithic material and directed excavations at Serra da
Capivara National Park. T.P. conducted the technological analysis. T.P., L.V.L.,
I.D.L.T. and M.H. discussed the implications of the results. T.P. wrote the paper
and supplementary online content with contributions from L.V.L., T.F., E.B.O.,
I.D.L.T. and M.H. T.P generated all figures, 3D models and video content, using
data recorded by M.H. and T.P.
Author Information Reprints and permissions information is available at The authors declare no competing financial
interests. Readers are welcome to comment on the online version of the paper.
Correspondence and requests for materials should be addressed to
T.P. ( or M.H. (
Reviewer Information Nature thanks S. Carvalho and H. Roche for their
contribution to the peer review of this work.
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OIT 2. We excavated Lasca OIT 1 (Extended Data Fig. 1a), located 120 m southwest
of Lasca OIT 2, beneath the sheer face of an approximately 7 m high conglomerate
outcrop that showed percussion marks indicative of previous SoS activity. A total
excavated area of 3 m
to a maximum depth of 0.4 m yielded 23 artefacts (20.7%)
at this site. We did not find human material, such as hearths, ceramic pieces, metal
objects, or ground stone at either site. Such items are ubiquitous in anthropogenic
sites elsewhere in SCNP
. This absence, along with direct observation of capuchins
creating the flaked surface assemblage, and the identical nature of the damage and
size of the recovered stones to those observed in use by capuchins, rules out human
production of the archaeological material.
No statistical methods were used to predetermine sample size. The experiments
were not randomized. The investigators were not blinded to allocation during
experiments and outcome assessment.
We identified the raw material of each artefact and performed technological
classification and analysis following commonly used technological attributes
For full details and definitions of the technological categories used in this analysis,
see the Supplementary Information. All data are available upon request.
The SoS percussion assemblage included 111 artefacts collected from surface and
archaeological capuchin activity locations in Serra da Capivara National Park
(SCNP), PIauí, Brazil. The surface collection (Lasca OIT surface; n = 60, 54.1%)
was produced by capuchins observed performing SoS percussion in September
2014, at a site later designated Lasca Oitente 2 (L asca OIT 2). The capuchins belong
to the Jurubeba group, which was first studied in March 2004 (ref. 20). SoS activity
primarily took place on a low (approximately 1 m high), narrow conglomerate
ridge associated with a much larger conglomerat ic outcrop (Fig. 1; Supplementary
Video 1). During this time a portion of the used assemblage dropp ed to the ground
immediately below the activity area, and was collected once the activity ceased.
Additional material was collected during surface surveys within the immediate
vicinity of Lasca OIT 2, at locations where isolated conglomerate blocks were used
by the same capuchin group for SoS percussion. This material was also analysed
as Lasca OIT surface.
The archaeological material comes from two excavations conducted in June
2015 (Extended Data Fig. 1), within the Jurubeba group range: Lasca OIT 1
(8° 52.460 S, 42° 37.977 W) and Lasca OIT 2 (8° 52.394 S, 42° 37.971 W). We
excavated both sites by hand in 5-cm levels, and sieved all sediment through a
5 mm mesh. Sediments at both sites consisted of light-brown, silty sand, with
gravel to cobble-sized inclusions, resulting from the in situ weathering of local
conglomerates. We distinguished capuchin tools from natural stones on the basis of
percussion marks and flaking features as described in the main text and below. The
Lasca OIT 2 excavation (Extended Data Fig. 1b) can be considered an extension of
the surface material collected in 2014 from the same site. An area of 3 m
to a maximum depth of 0.5 m yielded 28 SoS p erc ussion artefacts (25.2%) at Lasca
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Extended Data Figure 1 | Archaeological excavation of wild capuchin
SoS percussion sites, Serra da Capivara National Park. a, Lasca OIT1
excavation, each square is 1 × 1 m. b, The approach to Lasca OIT2,
which is located to the right of the conglomerate cliff face. c, Lasca
OIT2 excavation, note the low conglomerate ridge to the left, on which
capuchins were observed whilst performing SoS activities. Scale bar,
30 cm (see also Fig. 1).
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Extended Data Figure 2 | Examples of active hammers. a, Crushing impacts on multiple surfaces of an active hammer. b, Examples of impact points
and associated circular hertzian fractures on the surface of an active hammer. Scale bars are 5 cm, except for inset scale bars, which are 2 mm.
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Extended Data Figure 3 | Examples of SoS flaked hammer-stones. a, c, Flake detachment following a transverse active hammer fracture.
b, Unintentional radial reduction of flaked hammer-stone. df, Examples of complete active hammers with scars of accidental flakes. Scale bars
are 5 cm.
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Extended Data Figure 4 | Refits of flaked hammer-stones showing the
repeated detachment of unidirectional flakes. a, Refit Set 1 (artefact
numbers JC13 and JF7). b, Refit Set 2 (artefact numbers 225102a and
225102b). c, Refit Set 3 (artefact numbers 224881a and 224881b). d, Refit
Set 4 (artefact numbers JF3 and JC5). A, A2, B and C are designated planes
on each refit, corresponding to descriptions found in Supplementary
Information. Scale bars are 5 cm.
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Extended Data Figure 5 | Refits of flaked hammer-stones showing the
repeated detachment of unidirectional flakes and continued use of
broken active hammers. a, Refit Set 5 (artefact numbers JC11, JC12, JF23
and JF1). b, Refit Set 6 (artefact numbers JC6, JF2, JF14, JF4 and JF8)
(See also Supplementary Video 2). c, Refit Set 7 (artefact numbers
JC4 and JC10). A, A2, B, B2, C and C2 are designated planes on each refit,
corresponding to descriptions found in Supplementary Information. Scale
bars are 5 cm.
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Extended Data Figure 6 | Examples of complete flakes. af, Examples of complete flakes detached during capuchin SoS percussion. Scale bars are
in cm. Scale bars are 5 cm.
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Extended Data Table 1 | Absolute and relative frequencies and total weights (g) of technological categories identified in each Capuchin SoS
assemblage, Serra da Capivara National Park
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
Extended Data Table 2 | Dimensional data for all artefacts from Capuchin SoS assemblages and a comparison with
Pliocene–Pleistocene hominin artefacts
a, Dimension data for all technological categories identied in this study. b, Metric comparison of SCNP capuchin SoS percussion akes and aked hammer-stones with hominin
Pliocene–Pleistocene ake and core dimensions. Data and table adapted from Harmand et al. (2015).
© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
... Furthermore, some of the tools (mostly those used for digging) lacked macroscopic modifications, indicating that digging behaviors might be under-represented, and overlooked, in the archaeological record. Individuals from the same population have also been observed to unintentionally produce sharp-edged flakes by pounding stones directly against each other, some of which resemble Oldowan flakes (Proffitt et al., 2016). Similar evidence has now also been uncovered from wild macaque nut-cracking sites, challenging the intentional origin of lithic tool production and illustrating potential behavioral precursors to systematic stone knapping . ...
... Because of primate archaeology, ideas about a nonhuman origin for ancient archaeological records, previously attributed to humans, have begun to be taken seriously after important discoveries focused on capuchin monkeys (Agnolín & Agnolín, 2022;Proffitt et al., 2016). ...
The new field of primate archaeology investigates the technological behavior and material record of nonhuman primates, providing valuable comparative data on our understanding of human technological evolution. Yet, paralleling hominin archaeology, the field is largely biased toward the analysis of lithic artifacts. While valuable comparative data have been gained through an examination of extant nonhuman primate tool use and its archaeological record, focusing on this one single aspect provides limited insights. It is therefore necessary to explore to what extent other non-technological activities, such as non-tool aided feeding, traveling, social behaviors or ritual displays, leave traces that could be detected in the archaeological record. Here we propose four new areas of investigation which we believe have been largely overlooked by primate archaeology and that are crucial to uncovering the full archaeological potential of the primate behavioral repertoire, including that of our own: (1) Plant technology; (2) Archaeology beyond technology; (3) Landscape archaeology; and (4) Primate cultural heritage. We discuss each theme in the context of the latest developments and challenges, as well as propose future directions. Developing a more "inclusive" primate archaeology will not only benefit the study of primate evolution in its own right but will aid conservation efforts by increasing our understanding of changes in primate-environment interactions over time.
... Since the behaviors of past hominins cannot be directly observed, archaeologists rely on modern analogs in order to draw inferences about behavioral processes that produce patterning in the Oldowan archaeological record (Schiffer, 2010). While nonhuman primates have long been used as a frame of reference in human evolutionary studies (Wynn and McGrew, 1989;McGrew, 1992;Schick and Toth, 1994;Carvalho et al., 2013;Bandini et al., 2022), the emerging field of primate archaeology continues to provide new opportunities to explicitly examine how observable tool use behaviors manifest as material patterning in a natural setting (Carvalho et al., 2008(Carvalho et al., , 2013Haslam et al., 2009;Carvalho, 2011;Luncz et al., 2015Luncz et al., , 2016Luncz et al., , 2017Luncz et al., , 2019Proffitt et al., 2016Proffitt et al., , 2018. ...
... Even though the Oldowan is a simple core and flake technology, its associated archaeological record is remarkably diverse. While there is ongoing debate regarding what this diversity reflects (Gallotti, 2018), expanding primate archaeological research has shown that several specific aspects of the Early Stone Age archaeological record can be produced through nonhuman primate behaviors (McGrew, 1992;Carvalho et al., 2013;Proffitt et al., 2016Proffitt et al., , 2018Almeida-Warren et al., 2022). However, direct comparisons between nonhuman primates and hominin material cultures are limited due to the fundamental differences in the use of tools (Toth and Schick, 2009). ...
Living nonhuman primates have long served as a referential framework for understanding various aspects of hominin biological and cultural evolution. Comparing the cognitive, social, and ecological contexts of nonhuman primate and hominin tool use has allowed researchers to identify key adaptations relevant to the evolution of hominin behavior. Although the Oldowan is often considered to be a major evolutionary milestone, it has been argued that the Oldowan is rather an extension of behaviors already present in the ape lineage. This is based on the fact that while apes move tools through repeated, unplanned, short-distance transport bouts, they produce material patterning often associated with long-distance transport, planning, and foresight in the Oldowan. Nevertheless, remain fundamental differences in how Oldowan core and flake technology and nonhuman primate tools are used. The goal of the Oldowan hominins is to produce sharp-edged flakes, whereas nonhuman primates use stone tools primarily as percussors. Here, we present an agent-based model that investigates the explanatory power of the ape tool transport model in light of these differences. The model simulates the formation of the Oldowan record under the conditions of an accumulated short-distance transport pattern, as seen in extant chimpanzees. Our results show that while ape tool transport can account for some of the variation observed in the archaeological record, factors related to use-life duration severely limit how far an Oldowan core can be moved through repeated short-distance transport bouts. Thus, the ape tool transport has limitations in its ability to explain patterns in the Oldowan. These results provide a basis for discussing adaptive processes that would have facilitated the development of the Oldowan.
... Combining behavioural observation with the systematic documentation of emerging primate stone assemblages allows us to establish robust connections between stone tool behaviour and the material variation it produces. In addition, because primate stone tool use can be observed in the wild, primate archaeology also affords the opportunity to investigate how the intersection of tool-using behaviours, broader social contexts and ecological factors such as resource availability creates diversity in their material record [39,[44][45][46][47][48]. For example, percussive tools used by long-tailed macaques (Macaca fascicularis) in Thailand have been shown to vary in size, shape and damage patterns according to the foods being processed [48]. ...
... Environmental assessments of chimpanzee nut-cracking sites from West Africa have also shown how raw material properties influence both the development of damage and the accumulation of artefacts [44,49]. Furthermore, when percussive behaviours are undertaken on naturally occurring fine-grained isotropic materials among both macaques and capuchins there is a high chance of the formation of accidental sharp-edged flake assemblages [45,50]. Such studies are relevant to broader discussions in hominin behavioural evolution as they highlight the material diversity associated with various percussive behaviours. ...
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Archaeological evidence informs our understanding of the evolution of hominin behaviour. Such evidence is traditionally used to reconstruct hominin activities and intentions. In the Plio-Pleistocene, the presence or absence of specific tools and variation in artefact density is often used to infer foraging strategies, cognitive traits and functional activities. However, the Plio-Pleistocene archaeological record is known to be time-averaged and forms through the aggregation of repeated behavioural events over time. Thus, archaeological patterns do not reflect discrete episodes of activity, but rather the interaction of behaviour with environmental factors over time. However, little is known about how such interactions produce archaeological variation diversity. Primate archaeology can help address this research gap by providing the opportunity to observe how behaviour produces material patterns in a natural setting. This study, thus, examines how varying the material properties of stone and resource availability influence the artefactual signature of nut-cracking in a population of long-tailed macaques from Lobi Bay, Yao Noi island, Thailand. Results show that these interactions can produce a structured and diverse material signature in terms of artefact density and frequency of specific artefact types. These findings demonstrate how material patterns can emerge from long-term interactions between behaviour and environmental factors.
... Beyond their foraging activities, the capuchin behavior that has recently received particular attention is their stone-on-stone pounding (Mannu and Ottoni, 2009;Proffitt et al., 2016). Observed at the Oitenta area in Serra da Capivara (Brazil), during this activity, the individuals hit a quartzite cobble against another embedded cobble to pulverize the surface and lick the powder produced. ...
... Observed at the Oitenta area in Serra da Capivara (Brazil), during this activity, the individuals hit a quartzite cobble against another embedded cobble to pulverize the surface and lick the powder produced. What is more remarkable about this behavior is that the capuchin monkeys sometimes produce unintentional flakes that possess the same technological characteristics as intentionally knapping flakes in the hominin archaeological record, although they do not use the flakes for any cutting activities (Proffitt et al., 2016). ...
Since the launch of the Journal of Human Evolution fifty years ago, the archaeology of human origins and the evolution of culture have witnessed major breakthroughs with the identification of several new archaeological sites whose chronology has been slowly pushed back until the discovery of the earliest evidence of stone tool making at Lomekwi 3 (West Turkana, Kenya), at 3.3 Ma. Parallel to these discoveries , the study of wild primates, especially chimpanzees (Pan troglodytes), allowed the development of models to understand key aspects of the behavior of extinct hominin species. Indeed, chimpanzees possess an impressive diversity of tool-aided foraging behaviors, demonstrating that technology (and culture) is not exclusive to humans. Additionally, current research has also shown that wild capuchin monkeys (Sapajus libidinosus) and long-tailed macaques (Macaca fascicularis) also rely on stone percussive foraging behaviors. The investigation of these primates is boosting new interpretative models to understand the origins of stone flaking and the archaeological signature left by these primates. This review aims to present an examination of the state-of-the-art and the current advances made in the study of the earliest hominin technology and primate percussive behaviors. Overall, we argue that while it has been shown that extant primates can generate unintentional flakes, early hominins exhibited skills in the production and use of flakes not identified in primates. Nonetheless, we stand up to continue developing interdisciplinary approaches (i.e., primate archaeology) to study extant primates, as these endeavors are essential to move forward toward a detailed understanding of the technological foraging behaviors beyond the genus Homo. Finally, we discuss future challenges for the study of the emergence of stone technology.
... All Oldowan techniques were spontaneously re-invented by naive human subjects, who had not been told about these skills, had not seen them, and could not reverse engineer them (no Oldowan-like artefacts were provided). Unintentional production (see e.g., Motes-Rodrigo et al., 2022;Proffitt et al., 2016Proffitt et al., , 2023 and later use (see Westergaard and Suomi, 1995) of sharp flakes has been reported in extant primates, which demonstrates that the potential for such tools was likely clear if pre-Oldowan hominins used stone tools for percussion (which they likely did, see J. C. Thompson et al., 2019). The step to intentional production would likely be short if we assume a motivating need for sharp stone tools and possibly a slightly higher cognitive capacity in Oldowan hominins than in extant apes. ...
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It is widely believed that human culture originated in the appearance of Oldowan stone-tool production (circa 2.9 Mya) and a primitive but effective ability to copy detailed know-how. Cumulative cultural evolution is then believed to have led to modern humans and human culture via self-reinforcing gene-culture co-evolution. This outline evolutionary trajectory has come to be seen as all but self-evident, but dilemmas have appeared as it has been explored in increasing detail. Can we attribute even a minimally effective know-how copying capability to Oldowan hominins? Do Oldowan tools really demand know-how copying? Is there any other evidence that know-how copying was present? We here argue that this account, which we refer to as “Trajectory A”, may be a red herring, and formulate an alternative “Trajectory B” that resolves these dilemmas. Trajectory B invokes an overlooked group-level channel of cultural inheritance (the Social Protocell) whereby networks of cultural traits can be faithfully inherited and potentially undergo cumulative evolution, also when the underpinning cultural traits are apelike in not being transmitted via know-how copying (Latent Solutions). Since most preconditions of Trajectory B are present in modern-day Pan, Trajectory B may even have its roots considerably before Oldowan toolmaking. The cumulative build-up of networks of non-cumulative cultural traits is then argued to have produced conditions that both called for and afforded a gradual appearance of the ability to copy know-how, but considerably later than the Oldowan.
... If this is the case, and when combined with Pan and other nonhuman primate's known ability to flake stone objects (be it intentionally or not [Eren et al., 2020;Proffitt et al., 2016Proffitt et al., , 2018Proffitt et al., , 2023Schick et al., 1999;Toth et al., 1993]), it suggests that the absence of flaked stone tools in Pan's behavioral repertoire may not be linked to their upper limb anatomy. Further, it suggests that the presumed absence of flaked stone tools in pre-Lomekwian/Oldowan hominin populations may similarly not have been due to anatomical limitations in the upper limb. ...
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Objectives: Current evidence suggests that flaked stone tool technologies did not emerge until ~3.3–2.6 million-years-ago (Ma). It is often hypothesized that early hominin (principally Ardipithecus and early Australopithecus) manual anatomy may have prevented an earlier emergence, as the forceful precision grips essential to flake tool-use may have been ineffectively performed by these species. Marzke, Marchant, McGrew, and Reece (2015) observed potentially forceful pad-to-side precision grips being recruited by wild chimpanzees (Pan troglodytes) during feeding behaviors, indicating that Pan-like manual anatomy, and therefore potentially early hominin anatomy, may be capable of effectively securing flake stone tools during their use. Materials and Methods: Here, we report on the grips recruited by four captive, human-trained, bonobos (Pan paniscus) during the use of stone and organic tools, including flake stone tools during cutting behaviors. Results: It is revealed that pad-to-side precision grips are frequently recruited by these bonobos when securing stone flakes during cutting actions. In some instances, high forces could have been resisted and applied by the thumb and fingers. Discussion: While our analyzes are preliminary and limited to captive individuals, and Pan is not suggested to secure flakes with the same efficacy as Homo or Australopithecus, it points to early hominins potentially being able to perform the precision grips required to use flake stone tools. In turn, the ability to gain tangible benefits from the effective use of flake tools (i.e., gain energetic returns from processing food resources) may have been – at least anatomically – possible in early Australopithecus and other pre-Early Stone Age hominin species. In turn, hominin manual anatomy may not be a leading restriction on the emergence of the earliest stone tool technologies.
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For at least three million years, knapping stone has been practiced by hominin societies large and small, past and present. Thus, understanding knapping, knappers, and knapping cultures is fundamental to anthropological research around the world. Although there is a general sense that stone knapping is inherently dangerous and can lead to injury, little is formally, specifically, or systematically known about the frequency, location, or severity of knapping injuries. Toward this end, we conducted a 31-question survey of modern knappers to better understand knapping risks. Responses from 173 survey participants suggest that knapping injuries are a real and persistent hazard, even though a majority of modern knappers use personal protective equipment. A variety of injuries (lacerations, punctures, aches, etc.) can occur on nearly any part of the body. The severity of injury sustained by some of our participants is shocking, and nearly one-quarter of respondents reported having sought or received professional medical attention for a flintknapping-related injury. Overall, the results of this survey suggest that there would have likely been serious, even fatal, costs to knappers in past societies. Such costs may have encouraged the deployment of any social learning capacities possessed by hominins or delayed the learning or exposure of young infants or children to knapping.
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Stone tools reveal worldwide innovations in human behaviour over the past three million years. However, the only archaeological report of pre-modern non-human animal tool use comes from three Western chimpanzee (Pan troglodytes verus) sites in Côte d’Ivoire, aged between 4.3 and 1.3 thousand years ago (kya). This anthropocentrism limits our comparative insight into the emergence and development of technology, weakening our evolutionary models. Here, we apply archaeological techniques to a distinctive stone tool assemblage created by a non-human animal in the New World, the Brazilian bearded capuchin monkey (Sapajus libidinosus). Wild capuchins at Serra da Capivara National Park (SCNP) use stones to pound open defended food, including locally indigenous cashew nuts, and we demonstrate that this activity dates back at least 600 to 700 years. Capuchin stone hammers and anvils are therefore the oldest non-human tools known outside of Africa, opening up to scientific scrutiny questions on the origins and spread of tool use in New World monkeys, and the mechanisms — social, ecological and cognitive — that support primate technological evolution.
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The discovery of the earliest known stone tools at Lomekwi 3 (LOM3) from West Turkana, Kenya, dated to 3.3 Ma, raises new questions about the mode and tempo of key adaptations in the hominin lineage. The LOM3 tools date to before the earliest known fossils attributed to Homo at 2.8 Ma. They were made and deposited in a more C 3 environment than were the earliest Oldowan tools at 2.6 Ma. Their discovery leads to renewed investigation on the timing of the emergence of human-like manipulative capabilities in early hominins and implications for reconstructing cognition. The LOM3 artefacts form part of an emerging paradigm shift in palaeoanthropology, in which: tool-use and tool-making behaviours are not limited to the genus Homo ; cranial, post-cranial and behavioural diversity in early Homo is much wider than previously thought; and these evolutionary changes may not have been direct adaptations to living in savannah grassland environments. This article is part of the themed issue ‘Major transitions in human evolution'.
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O projeto, Síntese dos biomas e sociedades humanas da região do Parque Nacional Serra da Capivara, no Sudeste do Piauí, apoiado e financiado pelo Ministério de Ciência e Tecnologia do Brasil, abre um espaço editorial destinado a divulgar o conhecimento resultante do trabalho dos pesquisadores da Fundação Museu do Homem Americano – Fumdham – e outras entidades científicas associadas em rede no decorrer de três décadas de pesquisa nessa região. Cabe lembrar que inicialmente as pesquisas no Parque Nacional estiveram centradas nos sítios com pinturas rupestres pré-históricas em razão do seu extraordinário acervo, tanto pelo número de sítios achados, como sua densa concentração e seu estado de conservação. Em 1991, por essa riqueza gráfica e cultural, a Unesco inscreve o Parque Nacional Serra da Capivara na Lista do Patrimônio Mundial de Humanidade. As escavações arqueológicas foram no começo realizadas em função da procura de informações complementares sobre esse patrimônio cultural, mas rapidamente as descobertas extrapolam as metas e as expectativas formuladas. A inesperada antiguidade da presença humana na região requer, para desvendar esse universo desconhecido, uma abordagem de pesquisa interdisciplinar. Desde a criação do Projeto, em 1986, o tema de pesquisa proposto pela Fumdham foi definido como a interação do homem com o ambiente, desde a Pré-História até os dias atuais. Varias gerações de pesquisadores brasileiros e estrangeiros sucederam-se num fluxo contínuo de trabalhos interdisciplinares para configurar um mapa multidisciplinar que enquadrasse o tema central das pesquisas no Parque Nacional. A participação das diversas disciplinas na pesquisa evoluiu de maneira diferenciada, o que se traduz num grau distinto das colaborações. Algumas salientam o estado da arte, outras a evolução da pesquisa, outras, também, os aspectos inovativos e a introdução de novos dispositivos técnicos dentro do dispositivo de pesquisa.
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For several decades, it was largely assumed that stone tool use and production were abilities limited to the genus Homo. However, growing palaeontological and archaeological evidence, comparative extant primate studies, as well as results frommethodological advancements in biomechanics andmorphological analyses, have been gradually accumulating and now provide strong support for more advanced manual manipulative abilities and tool-related behaviours in pre-Homo hominins than has been traditionally recognized. Here, I review the fossil evidence related to early hominin dexterity, including the recent discoveries of relatively complete early hominin hand skeletons, and newmethodologies that are providing a more holistic interpretation of hand function, and insight into how our early ancestors may have balanced the functional requirements of both arboreal locomotion and tool-related behaviours. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
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The oldest direct evidence of stone tool manufacture comes from Gona (Ethiopia) and dates to between 2.6 and 2.5 million years (Myr) ago 1 . At the nearby Bouri site several cut-marked bones also show stone tool use approximately 2.5 Myr ago 2 . Here we report stone-tool-inflicted marks on bones found during recent survey work in Dikika, Ethiopia, a research area close to Gona and Bouri. On the basis of low-power microscopic and environmental scanning electron microscope observations, these bones show unambiguous stone-tool cut marks for flesh removal and percussion marks for marrow access. The bones derive from the Sidi Hakoma Member of the Hadar Formation. Established 40 Ar– 39 Ar dates on the tuffs that bracket this member constrain the finds to between 3.42 and 3.24 Myrago, and stratigraphic scaling between these units and other geological evidence indicate that they are older than 3.39 Myr ago. Our discovery extends by approximately 800,000 years the antiquity of stone tools and of stone-tool-assisted consumption of ungulates by hominins; furthermore, this behaviour can now be attributed to Australopithecus afarensis.
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Human evolutionary scholars have long supposed that the earliest stone tools were made by the genus Homo and that this technological development was directly linked to climate change and the spread of savannah grasslands. New fieldwork in West Turkana, Kenya, has identified evidence of much earlier hominin technological behaviour. We report the discovery of Lomekwi 3, a 3.3-million-year-old archaeological site where in situ stone artefacts occur in spatiotemporal association with Pliocene hominin fossils in a wooded palaeoenvironment. The Lomekwi 3 knappers, with a developing understanding of stone’s fracture properties, combined core reduction with battering activities. Given the implications of the Lomekwi 3 assemblage for models aiming to converge environmental change, hominin evolution and technological origins, we propose for it the name ‘Lomekwian’, which predates the Oldowan by 700,000 years and marks a new beginning to the known archaeological record.
The chimpanzees of Bossou in Guinea, West Africa, form a unique community which displays an exceptional array of tool use behaviors and behavioral adaptations to coexistence with humans. This community of Pan troglodytes verus has contributed more than three decades of data to the field of cultural primatology, especially chimpanzees’ flexible use of stones to crack open nuts and of perishable tools during foraging activities. The book highlights the special contribution of the long-term research at Bossou and more recent studies in surrounding areas, particularly in the Nimba Mountains and the forest of Diécké, to our understanding of wild chimpanzees’ tool use, cognitive development, lithic technology and culture. This compilation of research principally strives to uncover the complexity of the mind and behavioral flexibility of our closest living relatives. This work also reveals the necessity for ongoing efforts to conserve chimpanzees in the region. Chimpanzees have shed more light on our evolutionary origins than any other extant species in the world, yet their numbers in the wild are rapidly declining. In that sense, the Bossou chimpanzees and their neighbors clearly embody an invaluable cultural heritage for humanity as a whole. Readers can enjoy video clips illustrating unique behaviors of Bossou chimpanzees, in an exclusive DVD accompanying the hardcover or at a dedicated website described in the softcover.
The use of pounding stone tools (PSTs) is a customary behaviour in several wild populations of capuchin monkeys; most of these monkeys use PSTs primarily to open hard palm nuts. Here, we describe the use of PSTs in two not previously studied groups of capuchin monkeys (Sapajus libidinosus) in Serra da Capivara National Park (SCNP), northeastern Brazil, and compare them to other groups and populations. Capuchins from SCNP are one of the only known population that habitually use PSTs for several purposes other than nut processing, including cracking seeds and 24 fruits, breaking and/or enlarging holes in tree trunks or rocks, and pulverizing pebbles. Moreover, they use PSTs sequentially with probe stick tools to access hidden prey. The average size of PSTs was larger than the average locally available stones, suggesting active choice. The two groups exhibited more diversity in the use of PSTs than any other known population to date.