3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya

Journal name:
Nature
Volume:
521,
Pages:
310–315
Date published:
DOI:
doi:10.1038/nature14464
Received
Accepted
Published online

Abstract

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.

At a glance

Figures

  1. Geographic location of the LOM3 site.
    Figure 1: Geographic location of the LOM3 site.

    Map showing relation of LOM3 to other West Turkana archaeological site complexes.

  2. LOM3 lithological context.
    Figure 2: LOM3 lithological context.

    a, View of the excavation, facing east, showing relationship between surface, slope deposit, and in situ contexts containing the artefacts and fossils. Scale in midground is 20 cm. Lower-leftmost artefact is the anvil LOM3-2012-K18-2, shown in Fig. 5a. b, Topographic profile and stratigraphic units at site level showing the excavation zone (Ex), the geological trench made at the base of the section (GP); the artefacts and fossils derive from a series of lenses of sand and granules making up a ~1 m thick bed (Ch). c, Section at the excavation along bands I and J (indicated by the black line in Extended Data Fig. 1a) showing the sediments which form the fan deposits containing the artefacts.

  3. Chronostratigraphic framework for LOM3.
    Figure 3: Chronostratigraphic framework for LOM3.

    a, Chronostratigraphic framework for LOM3 (star) with generalized stratigraphic columns and magnetostratigraphic alignment to the geomagnetic polarity time scale (GPTS) in context of dates of tuffaceous markers (± 1 s.d.) and stratigraphic nomenclature for Members of the Nachukui Formation26, 30. A linearly interpolated date of 3.3 Ma for the in situ stone tools is consistent with the site’s magnetostratigraphic position within the reverse polarity interval that is correlated to reverse subchron C2An.2r (Mammoth Subchron) dated at 3.33–3.21 Ma31. b, Photograph facing north showing geographic and stratigraphic relationship between Toroto Tuff, paleobeach, and LOM3.

  4. Photographs of selected LOM3 artefacts.
    Figure 4: Photographs of selected LOM3 artefacts.

    a, In situ core (LOM3-2011-I16-3, 1.85 kg) and refitting surface flake (LOM3-2011 surf NW7, 650 g). Unifacial core, passive hammer and bipolar technique. Both the core and the flake display a series of dispersed percussion marks on cortex showing that percussive activities occurred before the removal of the flake, potentially indicating the block was used for different purposes. b, In situ unifacial core (LOM3-2012-H18-1, 3.45 kg), bipolar technique. See Extended Data Fig. 6b for more details. c, Unifacial core (LOM3-2012 surf 71, 1.84 kg), passive hammer technique. d, Flakes (LOM3-2012-J17-3 and LOM3-2012-H17-3) showing scars of previous removals on the dorsal face. See Supplementary Information part F for 3D scans of lithic artefacts.

  5. Photographs of selected LOM3 artefacts.
    Figure 5: Photographs of selected LOM3 artefacts.

    a, In situ passive element/anvil (LOM3-2012-K18-2, 12 kg). b, Passive element/anvil (LOM3-2012 surf 60, 4.9 kg). Both anvils a and b exhibit similar patterns of macroscopic wear consisting of superposed step fracturing in association with crushing and impacts marks. On a, damage is localized on a single lateral face, with battering marks present on one horizontal plane. On b, damage is distributed along a greater portion of the perimeter, but in this case no percussive marks are identifiable on the horizontal plane. In both cases, the intensity of the observed wear signature indicates a use in heavy-duty activities. c, Unifacial core (LOM3-2012 surf 90, 4.74 kg), bipolar technique and semi-peripheral exploitation. Inset shows crushing marks on the proximal surface of the cobble related to battering activities before or after the knapping of the core. See Supplementary Information part F for three-dimensional scans of lithic artefacts.

  6. Map and schematic section at LOM3.
    Extended Data Fig. 1: Map and schematic section at LOM3.

    a, Map showing xy coordinates of artefacts and fossils recovered in situ and from the surface at the site in 2011 and 2012. b, Schematic section showing vertical distribution of in situ artefacts and those located in the slope deposit at the excavation. Key is the same for both figures.

  7. Geology of the LOM3 site.
    Extended Data Fig. 2: Geology of the LOM3 site.

    a, Stratigraphic sections around LOM3 (locations in b), showing relationship of site to marker tuffs and lithofacies. Sections aligned relative to top of flat-pebble conglomerate unit. b, GPS coordinates of stratigraphic sections (WGS84 datum).

  8. Paleomagnetic data.
    Extended Data Fig. 3: Paleomagnetic data.

    a, Representative vector end-point plots of natural remanent magnetism thermal demagnetization data from specimen Toroto Tuff, tt2, wt59, wt50, wt45, wt36. Open and closed symbols represent the vertical and horizontal projections, respectively, in bedding coordinates. TD treatment steps: NRM, 100°, 150°, 200°, 250°, 300°, 350°, 400°, 450°, 475°, 500°, 525°, 550°, 575°, 600°, 625°, 650°, 660°, 670°, 675°, 680°, 690°, and 700°. V/M = 10 denotes a ~10 cc cubic specimen. b, Equal-area projections for Section 1 (left) and Section 2 (right) of the lower Lomekwi Member (see Fig. 3a). Open and closed symbols are projected onto the upper and lower hemisphere, respectively, in bedding coordinates. Plotted are ChRM sample-mean directions for accepted samples only (that is, those with MAD values <15°). Overall mean directions were calculated after inverting the northerly (normal) directions to common southerly (reverse) polarity.

  9. Paleoenvironmental reconstruction through pedogenic carbonate stable carbon isotopic analysis.
    Extended Data Fig. 4: Paleoenvironmental reconstruction through pedogenic carbonate stable carbon isotopic analysis.

    a, LOM3 paleosol δ13CVPDB values (‰) ± 1σ, number of analyses, fraction woody canopy cover (ƒwc) and percent C4 biomass contribution to soil CO2. Asterisk denotes nodules sampled at the LOM3 site, 2011-2b (see Extended Data Fig. 2a). b, Schematic box and whisker plots of ƒwc from the LOM3 (3.3 Ma, this study) and Gona33, 54, 55 (Busidima Fm, 2.5–2.7 Ma) lithic sites and other East African hominin localities from 3.2–3.4 Ma34, 55, 56, 57, 58, 59, 60, 61 relative to UNESCO structural categories of African vegetation32, 52. Grey box denotes 25th and 75th percentiles (interquartile range); whiskers represent observations within upper and lower fences (1.5 × interquartile range); black line shows mean value; grey line equals median value; black circles indicate mild outliers. c, Summary statistics of paleosol δ13CVPDB values and ƒwc from LOM3 (3.3 Ma) and Gona33, 54, 55 (2.5–2.7 Ma) lithic sites and other East African hominin localities from 3.2–3.4 Ma54, 55, 56, 57, 58, 59, 60, 61. LOM3 δ13CVPDB values are significantly lower than those from the Busidima Formation at Gona (t-test, P < 0.001) and have a mean value that indicate 18% more woody canopy cover. When compared to paleosol δ13CVPDB values of the Koobi Fora, Nachukui, Chemeron, and Hadar formations from 3.2 to 3.4 Ma, LOM3 δ13CVPDB values are not significantly different (one-way ANOVA, P > 0.05).

  10. Gradual uncovering of core I16-3 from in situ pliocene sediment.
    Extended Data Fig. 5: Gradual uncovering of core I16-3 from in situ pliocene sediment.

    a, Photograph showing square I16 at the beginning of excavation. Yellow line indicates north wall of square (July 16, 2011, 12.14 p.m.). b, Close-up of square I16 indicating complete burial of as-yet-uncovered artefact I16-3 (12.14 p.m.). c, Square I16 after excavation had begun and artefact I16-3 was initially exposed (2:11 p.m.). d, Close-up of artefact I16-3 after being initially exposed (2.12 p.m.). e, Close-up of artefact I16-3 after further excavation (3.02 p.m.). f, Square I16 after further excavation (5.32 p.m.). g, Close-up of artefact I16-3 after further excavation (5.34 p.m.). h, Close-up of artefact I16-3 after being completely freed from the surrounding matrix and flipped over for inspection (5.36 p.m.). i, Close-up of impression from under artefact I16-3 (5.47 p.m.).

  11. Photos of selected LOM3 artefacts compared with similar experimental cores.
    Extended Data Fig. 6: Photos of selected LOM3 artefacts compared with similar experimental cores.

    Together with the technological analysis of the archaeological material, our replication experiments suggest that the LOM3 knappers were using passive hammer technique, in which the core, usually held in both hands, is struck against a stationary object that serves as the percussor34 (also referred to as on-anvil, block on block or sur percuteur dormant35) and/or bipolar technique, in which the core is placed on an anvil and struck with a hammerstone34. a, Unifacial passive hammer cores. Left is archaeological piece LOM3-2012 surf 106 (2.04 kg); right is experimental piece Expe 55 (3.40 kg) produced using the passive hammer technique. Selection of relatively flat blocks with natural obtuse angles. The flake removal process starts from a slighly prominent part of the block (white arrows show the direction of removals). The removals tend to be invasive. The flaked surface forms a semi-abrupt angle with the platform surface. A slight rotation of the block ensures its semi-peripheral exploitation. b, Unifacial bipolar cores. Left are archaeological pieces LOM3-2012-H18-1 (left, 3.45 kg) and LOM3-2012 surf 64 (right, 2.58 kg); right are experimental pieces Expe 39 (left, 4.20 kg) and Expe 24 (right, 2.23 kg) produced using the bipolar technique. The block selected are thicker and more quadrangular in shape with natural angles 90°. Flakes are removed from a single secant platform (white arrows show the direction of removals). The flaked surface forms an abrupt angle with the other faces of the block. Impacts due to the contrecoups (white dots) are visible on the opposite edge from the platform.

  12. Photographs of selected LOM3 artefacts.
    Extended Data Fig. 7: Photographs of selected LOM3 artefacts.

    a, Passive element/anvil (LOM3-2012 surf 50,15 kg). Heavy sub-rectangular block displaying flat faces and therefore a natural morphology and weight which would enable stability. b, Hammerstone showing isolated impact points (LOM3-2012 surf 33, 3.09 kg) and c, Hammerstone showing isolated impact points (LOM3-2012 surf 54, 1.63 kg), associated with a flake-like fracture on one end.

Tables

  1. Numerical data on the LOM3 lithic assemblage (2011, 2012).
    Extended Data Table 1: Numerical data on the LOM3 lithic assemblage (2011, 2012).
  2. Comparison of whole flake and core dimensions between LOM3, early Oldowan sites and chimpanzee stone tool sites
    Extended Data Table 2: Comparison of whole flake and core dimensions between LOM3, early Oldowan sites and chimpanzee stone tool sites
  3. Comparison of anvils and percussors dimensions found at LOM3 site with anvils and percussors used by non-human primates in Bossou (wild chimpanzees, Pan troglodytes verus from ref. 41)
    Extended Data Table 3: Comparison of anvils and percussors dimensions found at LOM3 site with anvils and percussors used by non-human primates in Bossou (wild chimpanzees, Pan troglodytes verus from ref. 41)

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Author information

Affiliations

  1. Turkana Basin Institute, Stony Brook University, Stony Brook, New York 11794-4364, USA

    • Sonia Harmand,
    • Jason E. Lewis &
    • Louise Leakey
  2. CNRS, UMR 7055, Préhistoire et Technologie, Université Paris Ouest Nanterre La Défense, 21 allée de l’Université, 92023 Nanterre Cedex, France

    • Sonia Harmand,
    • Adrian Arroyo,
    • Nicholas Taylor &
    • Hélène Roche
  3. West Turkana Archaeological Project, P.O. Box 40658-00100, Ngara Rd, Nairobi, Kenya

    • Sonia Harmand,
    • Jason E. Lewis,
    • Craig S. Feibel,
    • Christopher J. Lepre,
    • Sandrine Prat,
    • Arnaud Lenoble,
    • Xavier Boës,
    • Rhonda L. Quinn,
    • Nicholas Taylor,
    • Sophie Clément,
    • Jean-Philip Brugal,
    • Sammy Lokorodi,
    • Christopher Kirwa &
    • Hélène Roche
  4. Department of Anthropology and Center for Human Evolutionary Studies, Rutgers University, New Brunswick, New Jersey 08901, USA

    • Jason E. Lewis &
    • Craig S. Feibel
  5. Department of Earth and Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854, USA

    • Craig S. Feibel,
    • Christopher J. Lepre,
    • Rhonda L. Quinn,
    • Richard A. Mortlock,
    • James D. Wright &
    • Dennis V. Kent
  6. Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA

    • Christopher J. Lepre &
    • Dennis V. Kent
  7. CNRS, UPR 2147, Dynamique de l’Evolution Humaine, 44 rue de l’Amiral Mouchez, 75014 Paris, France

    • Sandrine Prat &
    • Xavier Boës
  8. CNRS, UMR 5199 PACEA, Université de Bordeaux, 33615 Pessac, France

    • Arnaud Lenoble &
    • Michel Brenet
  9. Department of Sociology, Anthropology and Social Work, Seton Hall University, South Orange, New Jersey 07079, USA

    • Rhonda L. Quinn
  10. Inrap, Centre Mixte de Recherche Archéologique, Domaine de Campagne, 24620 Campagne, France

    • Michel Brenet
  11. Inrap, 34-36 avenue Paul-Vaillant Couturier, 93120 La Courneuve, France

    • Sophie Clément
  12. IPHEP, Institut de Paléoprimatologie, Paléontologie Humaine: Évolution et Paléoenvironnements, CNRS, UMR 7262, Université de Poitiers, Bât. B35 – TSA 51106, 6 rue Michel Brunet, 86073 Poitiers Cedex 9, France

    • Guillaume Daver
  13. Aix-Marseille Université, CNRS, MCC, UMR 7269, LAMPEA, 13094 Aix-en-Provence Cedex 2, France

    • Jean-Philip Brugal
  14. National Museums of Kenya, Department of Earth Sciences, Archaeology Section, P.O. Box 40658-00100 Ngara Rd, Nairobi, Kenya

    • Christopher Kirwa

Contributions

S.H. and J.E.L. directed field research and co-wrote the overall paper. C.S.F., C.J.L., A.L. and X.B. recorded sedimentological and stratigraphic data, conducted geological mapping, and wrote sections of the paper. C.S.F. interpreted tephra data. C.J.L. interpreted paleomagnetic data. S.P., J.-Ph.B., S.L., C.K. and L.L. conducted paleontological survey. S.P., J.-Ph.B. and L.L. analysed and interpreted fossil material. L.L. directed scanning of artefacts. S.P. laser scanned artefacts and excavation surfaces, and wrote sections of the paper. R.L.Q. interpreted isotopic data and wrote sections of the paper. C.S.F., C.J.L., R.L.Q., R.A.M., J.D.W. and D.V.K. analysed geological samples. G.D. developed protocols for tool replication experiments and wrote sections of the paper. S.H., H.R., N.T., M.B., S.C., S.L. and C.K. conducted archaeological survey and excavation. S.H., H.R., A.A., N.T. and M.B. analysed and interpreted lithic material and wrote sections of the paper. M.B. performed lithic replication experiments. S.C. provided spatial data. S.L. discovered the LOM3 site.

Competing financial interests

The authors declare no competing financial interests.

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Extended data figures and tables

Extended Data Figures

  1. Extended Data Figure 1: Map and schematic section at LOM3. (677 KB)

    a, Map showing xy coordinates of artefacts and fossils recovered in situ and from the surface at the site in 2011 and 2012. b, Schematic section showing vertical distribution of in situ artefacts and those located in the slope deposit at the excavation. Key is the same for both figures.

  2. Extended Data Figure 2: Geology of the LOM3 site. (848 KB)

    a, Stratigraphic sections around LOM3 (locations in b), showing relationship of site to marker tuffs and lithofacies. Sections aligned relative to top of flat-pebble conglomerate unit. b, GPS coordinates of stratigraphic sections (WGS84 datum).

  3. Extended Data Figure 3: Paleomagnetic data. (617 KB)

    a, Representative vector end-point plots of natural remanent magnetism thermal demagnetization data from specimen Toroto Tuff, tt2, wt59, wt50, wt45, wt36. Open and closed symbols represent the vertical and horizontal projections, respectively, in bedding coordinates. TD treatment steps: NRM, 100°, 150°, 200°, 250°, 300°, 350°, 400°, 450°, 475°, 500°, 525°, 550°, 575°, 600°, 625°, 650°, 660°, 670°, 675°, 680°, 690°, and 700°. V/M = 10 denotes a ~10 cc cubic specimen. b, Equal-area projections for Section 1 (left) and Section 2 (right) of the lower Lomekwi Member (see Fig. 3a). Open and closed symbols are projected onto the upper and lower hemisphere, respectively, in bedding coordinates. Plotted are ChRM sample-mean directions for accepted samples only (that is, those with MAD values <15°). Overall mean directions were calculated after inverting the northerly (normal) directions to common southerly (reverse) polarity.

  4. Extended Data Figure 4: Paleoenvironmental reconstruction through pedogenic carbonate stable carbon isotopic analysis. (718 KB)

    a, LOM3 paleosol δ13CVPDB values (‰) ± 1σ, number of analyses, fraction woody canopy cover (ƒwc) and percent C4 biomass contribution to soil CO2. Asterisk denotes nodules sampled at the LOM3 site, 2011-2b (see Extended Data Fig. 2a). b, Schematic box and whisker plots of ƒwc from the LOM3 (3.3 Ma, this study) and Gona33, 54, 55 (Busidima Fm, 2.5–2.7 Ma) lithic sites and other East African hominin localities from 3.2–3.4 Ma34, 55, 56, 57, 58, 59, 60, 61 relative to UNESCO structural categories of African vegetation32, 52. Grey box denotes 25th and 75th percentiles (interquartile range); whiskers represent observations within upper and lower fences (1.5 × interquartile range); black line shows mean value; grey line equals median value; black circles indicate mild outliers. c, Summary statistics of paleosol δ13CVPDB values and ƒwc from LOM3 (3.3 Ma) and Gona33, 54, 55 (2.5–2.7 Ma) lithic sites and other East African hominin localities from 3.2–3.4 Ma54, 55, 56, 57, 58, 59, 60, 61. LOM3 δ13CVPDB values are significantly lower than those from the Busidima Formation at Gona (t-test, P < 0.001) and have a mean value that indicate 18% more woody canopy cover. When compared to paleosol δ13CVPDB values of the Koobi Fora, Nachukui, Chemeron, and Hadar formations from 3.2 to 3.4 Ma, LOM3 δ13CVPDB values are not significantly different (one-way ANOVA, P > 0.05).

  5. Extended Data Figure 5: Gradual uncovering of core I16-3 from in situ pliocene sediment. (1,584 KB)

    a, Photograph showing square I16 at the beginning of excavation. Yellow line indicates north wall of square (July 16, 2011, 12.14 p.m.). b, Close-up of square I16 indicating complete burial of as-yet-uncovered artefact I16-3 (12.14 p.m.). c, Square I16 after excavation had begun and artefact I16-3 was initially exposed (2:11 p.m.). d, Close-up of artefact I16-3 after being initially exposed (2.12 p.m.). e, Close-up of artefact I16-3 after further excavation (3.02 p.m.). f, Square I16 after further excavation (5.32 p.m.). g, Close-up of artefact I16-3 after further excavation (5.34 p.m.). h, Close-up of artefact I16-3 after being completely freed from the surrounding matrix and flipped over for inspection (5.36 p.m.). i, Close-up of impression from under artefact I16-3 (5.47 p.m.).

  6. Extended Data Figure 6: Photos of selected LOM3 artefacts compared with similar experimental cores. (946 KB)

    Together with the technological analysis of the archaeological material, our replication experiments suggest that the LOM3 knappers were using passive hammer technique, in which the core, usually held in both hands, is struck against a stationary object that serves as the percussor34 (also referred to as on-anvil, block on block or sur percuteur dormant35) and/or bipolar technique, in which the core is placed on an anvil and struck with a hammerstone34. a, Unifacial passive hammer cores. Left is archaeological piece LOM3-2012 surf 106 (2.04 kg); right is experimental piece Expe 55 (3.40 kg) produced using the passive hammer technique. Selection of relatively flat blocks with natural obtuse angles. The flake removal process starts from a slighly prominent part of the block (white arrows show the direction of removals). The removals tend to be invasive. The flaked surface forms a semi-abrupt angle with the platform surface. A slight rotation of the block ensures its semi-peripheral exploitation. b, Unifacial bipolar cores. Left are archaeological pieces LOM3-2012-H18-1 (left, 3.45 kg) and LOM3-2012 surf 64 (right, 2.58 kg); right are experimental pieces Expe 39 (left, 4.20 kg) and Expe 24 (right, 2.23 kg) produced using the bipolar technique. The block selected are thicker and more quadrangular in shape with natural angles 90°. Flakes are removed from a single secant platform (white arrows show the direction of removals). The flaked surface forms an abrupt angle with the other faces of the block. Impacts due to the contrecoups (white dots) are visible on the opposite edge from the platform.

  7. Extended Data Figure 7: Photographs of selected LOM3 artefacts. (2,074 KB)

    a, Passive element/anvil (LOM3-2012 surf 50,15 kg). Heavy sub-rectangular block displaying flat faces and therefore a natural morphology and weight which would enable stability. b, Hammerstone showing isolated impact points (LOM3-2012 surf 33, 3.09 kg) and c, Hammerstone showing isolated impact points (LOM3-2012 surf 54, 1.63 kg), associated with a flake-like fracture on one end.

Extended Data Tables

  1. Extended Data Table 1: Numerical data on the LOM3 lithic assemblage (2011, 2012). (406 KB)
  2. Extended Data Table 2: Comparison of whole flake and core dimensions between LOM3, early Oldowan sites and chimpanzee stone tool sites (625 KB)
  3. Extended Data Table 3: Comparison of anvils and percussors dimensions found at LOM3 site with anvils and percussors used by non-human primates in Bossou (wild chimpanzees, Pan troglodytes verus from ref. 41) (236 KB)

Supplementary information

PDF files

  1. Supplementary Information (615 KB)

    This file contains Supplementary Text, Supplementary Tables 1-3 and Supplementary References.

Additional data