LETTERS
Evidence for stone-tool-assisted consumption of
animal tissues before 3.39 million years ago at Dikika,
Ethiopia
Shannon P. McPherron
1
, Zeresenay Alemseged
2
, Curtis W. Marean
3
, Jonathan G. Wynn
4
, Denne
´Reed
5
,
Denis Geraads
6
, Rene
´Bobe
7
& Hamdallah A. Be
´arat
8
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 un-
ambiguous 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 Myr ago, and stratigraphicscaling 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 con-
sumption of ungulates by hominins; furthermore, this behaviour
can now be attributed to Australopithecus afarensis.
The Dikika Research Project area is located in the Lower Awash
Valley (Ethiopia) and is bordered on the north by Gona and Hadar
and on the south by the Middle Awash research areas (Fig. 1). Work
there (led by Z.A.) began in 1999 and has focused on survey in Hadar
(.3.8 to 2.9 Myr ago) and Busidima Formation (2.7 to ,0.6 Myr ago)
deposits, both of which are exposed in their entirety within the project
area
3,4
. This work has resulted in the discovery of a diverse and well
preserved fauna, the discovery of several hominin fossils including a
nearly complete juvenile Australopithecus afarensis (DIK-1-1) and a
complete definition of the hominin-bearing Hadar Formation
3–6
.
In January 2009, the Dikika Research Project systematically col-
lected fossils from localities just opposite the DIK-1 locality in the
Andedo drainage, which predominantly exposes the Sidi Hakoma
(SH) Member of the Hadar Formation (3.42–3.24 Myr ago; Fig. 1).
Archaeological survey was conducted simultaneously in these same
localities. In the course of this work, four fossils were identified with
surface modifications which, based on field observations, resembled
stone-tool cut marks
7
. These fossils were subsequently studied with
optical and environmental scanning electron microscopy (ESEM)
(see Methods and Supplementary Information). Secondary electron
imaging (SEI) and energy dispersive X-ray (EDX) spectrometry data
show that the marks on two of these fossils (DIK-55-2 and DIK-55-3)
formed before fossilization. Optical and ESEM observations show
that the marks lack the morphology indicative of trampling and
biochemical marks, and that these two specimens have modifications
clearly indicative of stone tool use, including cutting and percussion.
Both bones were found on the surface at the same locality: DIK-55.
Stratigraphically this locality, an area of approximately 25 m 350 m,
can be placed into the section described previously for the nearby
DIK-1 locality. It is below a low ridge that exposes only the lowermost
sediments of the SH Member and below the level of a limestone
marker (SH-lm) with a stratigraphically scaled age of 3.39 Myr ago,
providing a minimum age for the site (Fig. 1 and Supplementary
Information). Nowhere in the entire Andedo drainage are sediments
above the lacustrine Triple Tuff 4 (TT-4) marker (3.24 Myr ago)
exposed, providing a minimum age for the entire section. Specimen
DIK-55-2 was found on the slope below the SH-lm marker and
DIK-55-3 was found on the flats just in front of this slope. Fossils from
this locality lack adhering matrix, indicating that they derive from a
,1.5-m-thick sand bed that outcrops here. This sand is unique com-
pared to many of the fossil-bearing sands of the SH Member (such as
at DIK-1) in that it is not strongly cemented and thus its fossils lack
adhering matrix.
DIK-55-2 (Fig. 2 and Supplementary Information) is a right rib
fragment of a large ungulate, probably size 4 (cow-sized) or larger.
Marks A1 and A2 are perpendicular to the cortical surface, V-shaped
in cross-section with internal microstriations and diagnosed as high-
confidence stone-tool cut marks. Mark B is a more obliquely oriented
mark that shaves off the bone surface within which are microstria-
tions, all consistent with a high-confidence stone-tool-inflicted mark
from cutting, scraping and/or percussion. An indentation (mark C)
with microstriations and crushing of the bone surface is a high-con-
fidence hammerstone percussion mark described in Supplementary
Information.
DIK-55-3 (Fig. 3 and Supplementary Information) is a femur shaft
fragment of a size 2 (goat-sized) young bovid. The surface is densely
marked (Fig. 3a). Mark A is perpendicular to the cortical surface and
has clear microstriations running out one end (Fig. 3b, c), diagnosed
as a high-confidence cut mark. Mark D (Fig. 3d–f) is a dense cluster.
One prominent mark within D (Fig. 3d) has crushing of the bone
surface with microstriations and is diagnosed as a high-confidence
percussion mark. Mark E (Fig. 3g, h) is obliquely oriented, shaves off
surface bone, has microstriations and a shouldered edge highly con-
sistent with a stone-tool cut mark. Marks H1 and H2 overlap. H1 has
clear microstriations, is associated with the broken edge of the bone
and swirls in a way typical of a percussion mark. H2 shaves off bone
1
Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, DeutscherPlatz 6, Leipzig 04103, Germany.
2
Department of Anthropology, California Academy
of Sciences, 55 Concourse Drive, San Francisco, California 94118, USA.
3
Institute of Human Origins, School of Human Evolution and Social Change, PO Box 872402, Arizona State
University, Tempe, Arizona 85287-2402, USA.
4
Department of Geology, University of South Florida, 4202 E Fowler Ave, SCA 528, Tampa, Florida 33620, USA.
5
University of Texas at
Austin, Department of Anthropology, 1 University Station C3200, Austin, Texas 78712, USA.
6
Centre National de la Recherche Scientifique, UPR 2147, 44 Rue de l’Amiral Mouchez,
Paris 75014, France.
7
Department of Anthropology, University of Georgia, Athens, Georgia 30602, USA.
8
School for Engineering of Matter, Transport and Energy, Ira A. Fulton Schools
of Engineering, Arizona State University, Tempe, Arizona 85287-6106, USA.
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surface and has clear microstriations, consistent with stone-tool cut
marks and a scraping motion. DIK-55-3 has other high-confidence
stone-tool-inflicted marks, and there is at least one mark (mark I) of
uncertain agency (Supplementary Information). This specimen does
not have any notches of the type that are sometimes associated with
hammerstone percussion on long bones
8–10
, but this may be owing to
post-depositional breakage of the edges that removed such notches.
The cut marks demonstrate hominin use of sharp-edged stone to
remove flesh from the femur and rib. The location and density of the
marks on the femur indicate that flesh was rather widely spread on
the surface, although it is possible that there could have been isolated
patches of flesh. The percussion marks on the femur demonstrate
hominin use of a blunt stone to strike the bone, probably to gain
access to the marrow. The external surfaces of ribs have thin sheaths
of flesh, so the scraping marks on the fossil rib suggest stripping off of
these sheaths.
The presence of stone-tool-modified bones and by implication the
use of stone tools at Dikika by 3.39 Myr ago greatly increases the
known antiquity of this behaviour. The earliest demonstration of
stone tool production known thus far is after 2.6 Myr ago at several
localities in Ethiopia and Kenya
1,11–14
. It is not possible to demon-
strate from the modified bones whether the stone tools were knapped
for this purpose or whether naturally occurring sharp-edged stones
were collected and used. No stone artefacts or sharp-edged stones
were found in association with the bones at DIK-55. However, stone
tool production and consequently archaeological accumulations are
not expected at this locality given the sedimentary environment
characterized by the palaeo-Awash River emptying into a nearby
lake
3,4
. In this relatively low-energy depositional environment, clasts
suitable for stone tool production are not present (few particles larger
than fine gravel, 8 mm diameter). Within the exposed SH Member, the
distance from DIK-55 to cobble-sized raw materials (.64 mm) is
,6 km (at Gorgore; Fig. 1). Thus, in this instance the absence of
evidence for stone tool production in the immediate vicinity of the
cut-marked bones may reflect landscape-level rawmaterial constraints.
The bones presented here are the earliest evidence for meat and
marrow consumption in the hominin lineage, pre-dating the known
evidence by over 800 kyr
2
. Pending new discoveries, the only hominin
species present in the Lower Awash Valley at 3.39 Myr ago to which
we can associate this tool use is A.afarensis
5,15
. Whether A. afarensis
a
bc
TT4
TT4
TT4
SHT
SHT
SHT
SHT
SHT
SHT
Andedo
Simbledere
Awash
Shibele
Gango Akidora
Ilanle
Simbledere Graben
54
48
59
4144
43
42
2
155
0 0.5 10.25 km
A
w
a
s
h
R
.
Gona
Hadar Ledi-Geraru
Dikika
DIK-1
DIK-55
Gorgore
DIK-2
40°40′0″E40°34′0″E
11°8
′
0
″
N11°4
′
0
″
N
02.551.25 km
~ Mam_b: 3.32 Myr ago
~ KMB: 3.30 Myr ago
SH-lm: 3.39 Myr ago
TT-4: 3.24 ± 0.01 Myr ago
SHT: 3.42 ± 0.03 Myr ago
B-g: 3.42 Myr ago
10 m
DIK-1
Andedo
SH-o: 3.24 Myr ago
SH-g: 3.30 Myr ago
DIK-55: 3.41 Myr ago
Elevation
Fossil localities
Geological sections
Geological markers
Sidi Hakoma Tuff
Triple Tuff 4
Fault (mapped)
Fault (inferred)
Monocline
Permanent rivers
Seasonal streams
Rivers
1
Ethiopia
High
:
720m
Low
:
440m
Figure 1
|
Geographic and stratigraphic location of DIK-55. a, Map of a
portion of the Dikika Research Project area showing DIK-55 (modified bone
locality), DIK-1 and DIK-2 (hominin localities), and relevant faults and
sections. b, Detailed map showing the position of the DIK-55 and
surrounding palaeontological localities. c, A composite stratigraphic column
of the Andedo drainage and surrounding Simbledere region showing the
position of the modified bones at DIK-55. Stratigraphic scaling of marker
units (SH-o, SH-g, SH-lm and B-g) are based on
40
Ar–
39
Ar ages of the Sidi
Hakoma Tuff (SHT) and TT-4 recalibrated to reflect an updated age of the
Fish Canyon Sanidine standard
28
. Stratigraphic scaling between these two
radiometrically dated tuffs provides a sedimentation rate of 427.8 m Myr
21
,
which is applied to the ages of the Basal gastropodite (B-g), Sidi Hakoma
limestone (SH-lm), DIK-1 excavation, Sidi Hakoma gastropodite (SH-g)
and Sidi Hakoma ostracodite (SH-o). These stratigraphically scaled ages are
consistent with a correlation to the position of the Kada Damoumou Basalt
,3.3 Myr ago and the lowermost boundary of the Mammoth
palaeomagnetic subchron within the Gauss chron (Mam_b.; chron 2An.2r at
3.319 Myr ago
29
; both are recorded elsewhere in the Hadar Formation
28,30
).
LETTERS NATURE
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also produced stone tools remains to be demonstrated, but the
DIK-55 finds may fit with the view that stone tool production pre-
dates the earliest known archaeological sites and was initially of low
intensity (one-to-a-few flakes removed per nodule) and distributed
in extremely low density scatters across the landscape such that its
archaeological visibility is quite low
16
. The evidence presented here
offers a first insight into an early phase of stone tool use in hominin
evolution that will improve our understanding of how this type of
behaviour originated and developed into later, well recognized, stone
tool production technologies.
METHODS SUMMARY
Bone surfaces were examined under 38–80 magnifications with adjustable
incident light from a bifurcated light source. ESEM was used to further docu-
ment marks and to collect SEI/EDX data (see below) but was not needed for
diagnosis and identification. Here (and in Supplementary Information) the
nested terminology of Gifford-Gonzalez
17
is used to draw inferential distinctions
between the actors responsible for producing the marks, the effectors used to
make the marks and causal action. A mark is considered high confidence in its
diagnosis to effector if it has all the criteria defined in the literature for that mark.
A distinction is made in mark diagnoses between general (stone tool, tooth, or
unidentifiable) and specific (cut mark versus percussion mark), with the caveat
that specific identifications are more tenuous given the overlap between per-
cussive and cutting damage indicated by these specimens.
2 cm
Ma rk A
Mark G1
Ma rk D
Mark H1
Mark H2
Ma rk E
Mark A Mark D
Mark G1
Mark H Mark E
a
bc
d
e
g
f
h
i
1 mm
1 mm
1 mm
1 mm
1 mm
Figure 3
|
Stone-tool-inflicted marks on DIK-55-3, a femur shaft of a size 2
young bovid. a, The exterior surface of DIK-55-3. The bone is oriented such
that the proximal end is to the right. Dashed rule, 4 cm. The location of
each of the surface marks is shown in close-up in b–i.b, Mark A (high-
confidence stone-tool-inflicted mark) under low-power optical
magnification shows clear microstriations indicative of cutting with a stone
tool; the yellow rectangle shows the position of c.c, ESEM image further
documenting microstriations. d, Mark G1 leading into the large area of
clustered damage designated mark D; D shows both stone-tool percussion
damage (shown in yellow rectangle that demarcates f) and recurrent cutting
by a stone tool. e, Continuation of mark D showing high-confidence stone-
tool-inflicted marks. f, ESEM image showing microstriations indicative of
stone tool action. g, ESEM image of the area indicated by the rectangle in hof
mark E showing microstriations indicative of stone tool action. c,f,g, Scale
bars, 100 mm. h, Mark E (high-confidence stone-tool-inflicted mark) under
low-power optical magnification possibly produced by a slicing motion from
the distal end. i, Marks H1 and H2 under low-power magnification, both
high-confidence stone-tool-inflicted marks; H1 is probably a percussion
mark and H2 is probably a cut mark. b–i, The direction of the femur head is
indicated by the black arrows on the scale, which is 5 mm. See
Supplementary Information for marks B, C, F and I, not shown here.
a
b
de
c
Mark A1 and A2
Mark A1
Mark B
Mark A2
Mark B
1 mm
Mark C
2 cm
1 mm
Figure 2
|
Stone-tool-inflicted marks on DIK55-2, a rib of a probably size 4
or larger ungulate. a, The exterior surface of DIK-55-2, and the location of
each of the surface marks. The rib is oriented such that the rib head (broken
off) would be to the left. Dashed rule, 4 cm. b, Marks A1 and A2 (high-
confidence stone-tool cut marks) under low-power optical magnification;
the yellow rectangle demarcates c. Scale bar, 5 mm. c, ESEM image showing
microstriations indicative of cutting with a stone tool. Scale bar, 100 mm.
d, Mark B (high-confidence stone-tool-inflicted mark) under low-power
optical magnification, indicative of a cutting and scraping action or
percussion; the yellow rectangle demarcates e. Scale bar, 5 mm. e, ESEM
image showing microstriations indicative of stone tool action. Scale bar,
500 mm. b–e, The direction of the rib head is indicated by the black arrows.
See Supplementary Information for the details of mark C.
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Modern collection damage was assessed visually and chemically. The patina
inside the surface marks resembles the surface patina and not the lighter colour
of the interior fossil bone made visible by some modern damage on the ends. The
elemental composition, measured with EDX spectrometry, of the marks and
adjacent surfaces indicates that fossilization occurred after mark formation
(Supplementary Information). EDX spectrometry was also applied to a rock
fragment, probably of igneous origin, embedded in one mark (Supplementary
Information). The marks were assessed for criteria described as indicative of
biochemical damage
18,19
and of trampling
20,21
and found to lack key criteria
(Supplementary Information). Finally, we used well known and described mor-
phological criteria
9,18,19,22–27
to distinguish between cut marks, percussion marks
and tooth marks. Further comparisons were made to experimentally generated
stone cut-marked, percussion-marked and carnivore-tooth-marked com-
parative specimens. Identifications were blind tested for correspondence
between three experienced taphonomists and zooarchaeologists who examined
the specimens under the same light-microscope conditions. The results showed a
high correspondence and agreement that most marks were stone-tool inflicted
(Supplementary Information).
Received 9 April; accepted 1 June 2010.
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Supplementary Information is linked to the online version of the paper at
www.nature.com/nature.
Acknowledgements We thank the Authority for Research and Conservation of
Cultural Heritage, the National Museum of Ethiopia, the Ministry of Tourism and
Culture and the Afar regional government for permits and support; C. Mesfin,
Z. Bedaso, T. Gebreselassie, Mesfin Mekonnen, H. Defar, A. Zerihun, G. Senbeto,
Mogues Mekonnen, W. Aberra, T. Yifru and the people of the Dikika area for field
assistance. We also thank the administration of Adaytu town and members of the
Ethiopian armed forces. Funds for the 2009 field season were provided by the
California Academy of Sciences. Travel expenses for D.G., S.P.M., D.R. and J.G.W.
were covered by their respective institutions. C.W.M. and H.A.B. acknowledge the
assistance of the research professionals in the John M. Cowley Center for High
Resolution Electron Microscopy, LE-CSSS, ASU in conducting the ESEM imaging,
and J. Thompson and S. Lansing for participating in the blind test. Z.A. thanks
P. Mollard and K. Berge for assistance during fieldwork preparations.
Author Contributions S.P.M. is the project archaeologist. Z.A. is the head of the
project and palaeoanthropologist. C.W.M. described and analysed the fossil bone
specimens and surface modifications. J.G.W. is the project geologist. Fauna were
analysed by Z.A., D.R. (micromammals and GIS), D.G. (biostratigraphy), R.B.
(palaeoenvironments). H.A.B. conducted the ESEM/SEI/EDX study. All authors
contributed to the writing of this paper.
Author Information Reprints and permissions information is available at
www.nature.com/reprints. The authors declare no competing financial interests.
Readers are welcome to comment on the online version of this article at
www.nature.com/nature. Correspondence and requests for materials should be
addressed to S.P.M. (mcpherron@eva.mpg.de).
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