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A 130,000-year-old archaeological site in southern California, USA

Nature volume 544, pages 479483 (27 April 2017) | Download Citation

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The earliest dispersal of humans into North America is a contentious subject, and proposed early sites are required to meet the following criteria for acceptance: (1) archaeological evidence is found in a clearly defined and undisturbed geologic context; (2) age is determined by reliable radiometric dating; (3) multiple lines of evidence from interdisciplinary studies provide consistent results; and (4) unquestionable artefacts are found in primary context1,2. Here we describe the Cerutti Mastodon (CM) site, an archaeological site from the early late Pleistocene epoch, where in situ hammerstones and stone anvils occur in spatio-temporal association with fragmentary remains of a single mastodon (Mammut americanum). The CM site contains spiral-fractured bone and molar fragments, indicating that breakage occured while fresh. Several of these fragments also preserve evidence of percussion. The occurrence and distribution of bone, molar and stone refits suggest that breakage occurred at the site of burial. Five large cobbles (hammerstones and anvils) in the CM bone bed display use-wear and impact marks, and are hydraulically anomalous relative to the low-energy context of the enclosing sandy silt stratum. 230Th/U radiometric analysis of multiple bone specimens using diffusion–adsorption–decay dating models indicates a burial date of 130.7 ± 9.4 thousand years ago. These findings confirm the presence of an unidentified species of Homo at the CM site during the last interglacial period (MIS 5e; early late Pleistocene), indicating that humans with manual dexterity and the experiential knowledge to use hammerstones and anvils processed mastodon limb bones for marrow extraction and/or raw material for tool production. Systematic proboscidean bone reduction, evident at the CM site, fits within a broader pattern of Palaeolithic bone percussion technology in Africa3,4,5,6, Eurasia7,8,9 and North America10,11,12. The CM site is, to our knowledge, the oldest in situ, well-documented archaeological site in North America and, as such, substantially revises the timing of arrival of Homo into the Americas.

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  • 08 May 2017

    An earlier version of Fig. 2a without a scale bar was incorrectly used in the HTML and PDF versions; this has been updated.


  1. 1.

    The earliest Americans. Science 166, 709–715 (1969)

  2. 2.

    in Early Man in the New World (ed. ) 65–72 (Sage Publications, 1983)

  3. 3.

    et al. Environment and behavior of 2.5-million-year-old Bouri hominids. Science 284, 625–629 (1999)

  4. 4.

    Olduvai Gorge. Vol. 3. Excavations in Beds I and II 19601963 (Cambridge Univ. Press, 1971)

  5. 5.

    & The first use of bone tools: a reappraisal of the evidence from Olduvai Gorge, Tanzania. Palaeont. Afr. 40, 95–158 (2004)

  6. 6.

    et al. On meat eating and human evolution: a taphonomic analysis of BK4b (Upper Bed II, Olduvai Gorge, Tanzania), and its bearing on hominin megafaunal consumption. Quat. Int. 322–323, 129–152 (2014)

  7. 7.

    & The use of elephant bones for making Acheulian handaxes: a fresh look at old bones. Quat. Int. 406, 227–238 (2016)

  8. 8.

    et al. The use of Proboscidean remains in every-day Palaeolithic life. Quat. Int. 126–128, 179–194 (2005)

  9. 9.

    , & Palaeolithic bone tools from the 10th excavation season at Tategahana, Lake Nojiri, central north Japan. Quat. Res. 29, 89–103 (1990)

  10. 10.

    in Megafauna and Man: Discovery of America’s Heartland (eds , & ) 86–99 (Scientific Papers 1 Mammoth Site of Hot Springs, 1990)

  11. 11.

    Mammoth bone quarrying on the late Wisconsinan North American grasslands. in The World of Elephants 439–443 (2001)

  12. 12.

    Mastodon butchery by North American Paleo-Indians. Nature 308, 271–272 (1984)

  13. 13.

    , & State Route 54 Paleontological Mitigation Program: Final Report (San Diego Natural History Museum, 1995)

  14. 14.

    in Advances in Archaeological Method and Theory Vol. 8 (ed. ) 157–235 (Academic, 1985)

  15. 15.

    , , , & Experimental protocols for the study of battered stone anvils from Olduvai Gorge (Tanzania). J. Archaeol. Sci. 40, 313–332 (2013)

  16. 16.

    et al. Production and use of percussive stone tools in the Early Stone Age: Experimental approach to the lithic record of Olduvai Gorge, Tanzania. J. Archaeol. Sci. Rep. 2, 367–383 (2015)

  17. 17.

    & Experimental patterns of hammerstone percussion damage on bones: implications for inferences of carcass processing by humans. J. Archaeol. Sci. 33, 459–469 (2006)

  18. 18.

    & A quantitative diagnosis of notches made by hammerstone percussion and carnivore gnawing on bovid long bones. Am. Antiq. 59, 724–748 (1994)

  19. 19.

    Frequencies of spiral and green-bone fractures of ungulate limb bones in modern surface assemblages. Am. Antiq. 48, 102–114 (1983)

  20. 20.

    Taphonomy and Archaeology in the Upper Pleistocene of Northern Yukon Territory: A Glimpse of the Peopling of the New World (Archaeological Survey of Canada, Paper No. 94, National Museum of Man, 1980)

  21. 21.

    Late Pleistocene Eemian hyena and steppe lion feeding strategies on their largest prey – Palaeoloxodon antiquus Falconer and Cautley 1845 at the straight-tusked elephant graveyard and Neanderthal site Newmark-Nord Lake 1, Central Germany. Archaeol. Anthropol. Sci. 6, 271–291 (2014)

  22. 22.

    Vertebrate Taphonomy (Cambridge Univ. Press, 1994)

  23. 23.

    , & The evolution and cultural transmission of percussive technology: integrating evidence from palaeoanthropology and primatology. J. Hum. Evol. 57, 420–435 (2009)

  24. 24.

    & New estimates of tooth mark and percussion mark frequencies at the FLK Zinj site: the carnivore-hominid-carnivore hypothesis falsified. J. Hum. Evol. 50, 170–194 (2006)

  25. 25.

    Taphonomic and ecologic information from bone weathering. Paleobiology 4, 150–162 (1978)

  26. 26.

    Taphonomy and Population Dynamics of an Early Pliocene Vertebrate Fauna, Knox County, Nebraska (Contributions to Geology, Special Paper 1, Univ. Wyoming, 1969)

  27. 27.

    . & in IV Simposio Internacianal: El Hombre Temprano en America (eds ., , . & ) 85–105 (Instituto Nacional de Anthropologia e Historia, 2012)

  28. 28.

    & A diffusion-adsorption model of uranium uptake by archaeological bone. Geochim. Cosmochim. Acta 60, 2139–2152 (1996)

  29. 29.

    , & U-series dating of bone using the diffusion-adsorption model. Geochim. Cosmochim. Acta 66, 4273–4286 (2002)

  30. 30.

    , & U-series dating of bone in an open system: the diffusion–adsorption–decay model. Quat. Geochronol. 9, 42–53 (2012)

  31. 31.

    Soil Survey Division Staff. Soil Survey Manual (US Department of Agriculture, 1993)

  32. 32.

    Soils and Geomorphology 3rd edn (Oxford Univ. Press, 1999)

  33. 33.

    & Mineralogy and Optical Mineralogy (Mineralogical Society of America, 2007)

  34. 34.

    & X-ray Diffraction and the Identification and Analysis of Clay Minerals 2nd edn (Oxford Univ. Press, 1997)

  35. 35.

    Orientation and distribution of fossils as environmental indicators. Guidebook: Nineteenth Field Conference of the Wyoming Geological Association. 219–229 (1965)

  36. 36.

    & The Anatomy of the Domestic Animals (W. B. Saunders and Co., 1953)

  37. 37.

    in Mastodon Paleobiology, Taphonomy, and Palaeoenvironment in the Late Pleistocene of New York State: Studies on the Hyde Park, Chemung, and North Java Sites (eds . & ) 197–290 (Paleontological Research Institution, 2008)

  38. 38.

    in Archaeology in Practice: a Student Guide to Archaeological Analyses 2nd edn (eds & ) 232–263 (Malden: Blackwell Publishing, 2014)

  39. 39.

    A new approach to identifying bone marrow and grease exploitation: why the “indeterminate” fragments should not be ignored. J. Archaeol. Sci. 28, 401–410 (2001)

  40. 40.

    et al. Evidence for kill-butchery events of early Paleolithic age at Kostenski, Russia. J. Archaeol. Sci. 37, 1073–1089 (2010)

  41. 41.

    & Bone degradation and environment: understanding, assessing and conducting archaeological experiments using modern animal bones. Int. J. Osteoarchaeol. 25, 201–212 (2015)

  42. 42.

    VisualSFM: A Visual Structure from Motion System. (2011)

  43. 43.

    SiftGPU: A GPU Implementation of Scale Invariant Feature Transform (SIFT). (2007)

  44. 44.

    . & Multi-view reconstruction preserving weakly-supported surfaces. IEEE Conference on Computer Vision and Pattern Recognition (CVPR, 2011)

  45. 45.

    et al. Improvements in 230Th dating, 230Th and 234U half-life values, and U–Th isotopic measurements by multi-collector inductively coupled plasma mass spectrometry. Earth Planet. Sci. Lett. 371–372, 82–91 (2013)

  46. 46.

    , , , & Precision measurements of half-lives and specific activities of 235U and 238U. Phys. Rev. C 4, 1889–1906 (1971)

  47. 47.

    & Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth Planet. Sci. Lett. 36, 359–362 (1977)

  48. 48.

    , & The Schwartzwalder uranium deposit, II: age of uranium mineralization and lead isotope constraints on genesis. Econ. Geol. 80, 1858–1871 (1985)

  49. 49.

    & U–Th radioactive disequilibrium analyses for JCp-1, coral reference distributed by the Geological Survey of Japan. Geochem. J. 40, 537–541 (2006)

  50. 50.

    , & New TIMS constraints on the uranium-238 and uranium-234 in seawaters from the main ocean basins and Mediterranean Sea. Mar. Chem. 80, 79–93 (2002)

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The following individuals worked at the CM site: L. Agenbroad (deceased), B. Agenbroad, J. Mead, M. Cerutti, M. Colbert, C. P. Majors, B. Riney, D. Swanson (deceased) and S. Walsh (deceased). M. Hager was instrumental in ensuring completion of this project. J. Berrian and D. Van der Weele photographed bone and rock specimens and K. Johnson (SDNHM), S. Donohue (SDNHM), C. Abraczinskas (UMMP) and E. Parrish produced various main and Extended Data Figures. E. Hayes, J. Field and V. Rots assisted with photography and interpretation of use-wear on cobbles. C. Musiba and K. Alexander provided photographs of the experimental elephant bone breakage. E. Duke provided the photographs of the experimental anvil wear on bone. Financial support was provided by Caltrans-District 11, P. Boyce and D. Fritsch, The James Hervey Johnson Charitable Educational Trust, The National Geographic Society (Research Grant 4971-93), The Walton Family Foundation (at the recommendation of J. and C. Walton) and the many donors to the Center for American Paleolithic Research. Any use of trade, firm or product names is for descriptive purposes only and does not imply endorsement by the US Government.

Author information


  1. Center for American Paleolithic Research, 27930 Cascade Road, Hot Springs, South Dakota, USA

    • Steven R. Holen
    •  & Kathleen A. Holen
  2. Department of Paleontology, San Diego Natural History Museum, San Diego, California, USA

    • Steven R. Holen
    • , Thomas A. Deméré
    • , Richard A. Cerutti
    •  & Kathleen A. Holen
  3. Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, USA

    • Daniel C. Fisher
    •  & Adam N. Rountrey
  4. Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA

    • Daniel C. Fisher
  5. Centre for Archaeological Science, School of Earth and Environmental Sciences, Faculty of Science Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia

    • Richard Fullagar
  6. Geosciences and Environmental Change Science Center, United States Geological Survey, Denver, Colorado, USA

    • James B. Paces
  7. Colorado Desert District Stout Research Center, California Department of Parks and Recreation, Borrego Springs, California, USA

    • George T. Jefferson
    •  & Lawrence Vescera
  8. Department of Earth Science, Adams State University, Alamosa, Colorado, USA

    • Jared M. Beeton


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R.A.C. discovered the CM site and led the excavation team. T.A.D. and S.R.H. conceived the study. S.R.H., T.A.D., K.A.H., R.A.C., D.C.F. and G.T.J. analysed the mastodon bone modifications. R.A.C., T.A.D., S.R.H., K.A.H. and D.C.F. identified refits of bones and cobbles. R.F. conducted the lithic use-wear analysis. J.M.B. and T.A.D. conducted the geological and soils analysis. J.B.P. conducted the U-series dating. D.C.F. provided mastodon skeletal identifications and analyses. G.T.J. and L.V. conducted the comparative taphonomic analysis. D.C.F. and A.N.R. produced the 3D models and videos of bone and cobbles. S.R.H., K.A.H. and R.F. conducted the experimental elephant, cow and kangaroo bone breakage. S.R.H., T.A.D., D.C.F., R.F., J.B.P., G.T.J., J.M.B. and K.A.H. wrote the paper with contributions by all other co-authors.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Steven R. Holen or Thomas A. Deméré.

Reviewer Information Nature thanks E. Hovers and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    This file contains a discussion of the Geological and Depositional Setting of the Cerutti Mastodon site, Sediment Analysis for the site, Usewear and Impact Marks on CM Hammerstones and Anvils, Proboscidean Taphonomy (natural vs. cultural modification of limb bones), Experimental Breakage of Elephant (and other animal) Limb Bone, Taphonomy of Skeletal Remains, Radiocarbon and Optically Stimulated Luminescence Dating, Uranium-series Ages and Asian Origins of Early Humans on the West Coast of North America. Collectively, this material supports our interpretation of the Cerutti Mastodon site.


  1. 1.

    Animation of a 3D surface model of CM-222 (also illustrated in Fig. 2c), an “impact flake” made on cortical bone of Mammut

    View using Windows Media Player (select “Repeat” to loop video, showing scale bar at end of each cycle; remove cursor from frame to close progress bar and maximize viewing area) or by dragging file onto an open tab in Chrome (after video starts, right-click within frame, uncheck “Show controls” option and check “Loop” option to watch several cycles). Upper panel of animation shows model with vertex-color; lower panel shows a mostly grayscale model that displays topography more clearly. Color overlay on grayscale model: yellow, impact surface; red, convex ovoidal surface (bulb of percussion; dark color proximal to point of impact; light color distal to point of impact); blue, concave ovoidal surface (negative bulb of percussion; dark color proximal to point of impact; light color distal to point of impact); dotted blue line, margin of hinge fracture at periphery of negative bulb. Symmetry axis of ovoidal impactor indicates trajectory of impact responsible for flake. See caption of Fig. 2 for additional annotation. Animation starts with ventral view of flake, rotates to dorsal view showing a negative flake scar and hinge fracture, continues to a slightly elevated lateral view showing topography of both sides of flake and angle of impactor, tilts to look down on hinge fracture, rotates to look down axis of impactor, and then ends looking straight down on the impact surface. This type of flake is clearly produced by percussion.

  2. 2.

    Animation of a 3D surface model of CM-230 (also illustrated in Fig. 2b), a cone-flake made on cortical bone of Mammut

    See description of Supplementary Video 1 for viewing directions, general description of animation, and colour code for lower (grayscale) model. Additional annotation in caption of Fig. 2. Pause in animation offers a low-angle view along the ventral fracture surface, showing the convex curvature of a subtle bulb of percussion (red) just below the (yellow) impact surface (no impactor shown with this model, but trajectory of impact would have been normal to impact surface). This type of flake is clearly produced by percussion.

  3. 3.

    Animation of a 3D surface model of CM-288 (also illustrated in Extended Data Fig. 4a-e), a spiral-fractured piece of cortical bone from one of the Mammut femora

    See description of Supplementary Video 1 for viewing directions, general description of animation, and color code for lower (grayscale) model. Animation shows a simple rotation of the models. The grayscale version is portrayed with an abstract impactor and anvil, both of which rotate with the bone fragment. The form of this fragment is characteristic of green-bone fracturing.

  4. 4.

    Animation of a 3D surface model of CM-340 (also illustrated in Fig. 2d), a large fragment of femoral cortical bone of Mammut

    See description of Supplementary Video 1 for viewing directions, general description of animation, and color code for lower (grayscale) model. Animation begins with a simple rotation of the fragment, then zooms in to the area of impact, where two concentric negative (concave) flake scars (light blue patches) bracket a partial, undetached flake, before elevating to show the impact notch on the outer cortical surface (yellow) just above the undetached flake. No impactor is shown with this model, to avoid obscuring detail, but trajectory of impact would have been normal to impact surface. The form of this fragment and impact notch are characteristic of percussion-induced green-bone fracturing.

  5. 5.

    Animation of a 3D surface model of CM-438a (also illustrated in Fig. 2a), a cone-flake made on cortical bone of Mammut

    See description of Supplementary Video 1 for viewing directions, general description of animation, and color code for lower (grayscale) model. Animation starts with a view of the ventral surface, rotates 360º, passing the dorsal surface, then continuing in an upward arc to look down on the cortical (impact) surface, then reversing to return to the starting point. No impactor is shown with this model, but trajectory of impact would have been normal to impact surface. This type of flake is clearly produced by percussion.

  6. 6.

    Animation of 3D surface models of CM-255, 263a, 263b, 329 and 390, fragments of thick cortical bone (probably femoral) of Mammut

    See description of Supplementary Video 1 for viewing directions, general description of animation, and colour code for lower (grayscale) model. Animation shows a 360º rotation of the entire assembly of bone fragments, then shifts to a more elevated perspective for a second 360º rotation. During this second turn, the fragments fly apart and then together again to show how they fit precisely to reconstruct the larger assembly.

  7. 7.

    Animation of 3D surface models of CM-109, 254, 262, 283, 284, 304 and 423, fragments of a pegmatite hammerstone shown in the map in Fig. 3 (CM-423 is also shown in Extended Data Figs. 3f and 5g,h).

    See description of Supplementary Video 1 for viewing directions, general description of animation, and colour code for lower (grayscale) model. Animation begins by rotating about 180º near the equatorial plane of the oblate spheroid this assembly resembles, then rises to look down on this plane. During the next 180º rotation, the fragments fly apart and then together again to show how they fit precisely to reconstruct the original, unbroken cobble.

  8. 8.

    Video record of experimental breakage of elephant limb bone in Tanzania and later experiments in Colorado, USA.

    Multiple impacts with a hafted hammerstone succeed in breaking a femur across a proximal portion of the diaphysis. Later, an unhafted hammerstone is used to remove flakes from the cortical wall of a transversely fractured bone. Replicated green-bone fractures show properties comparable to those of specimens from the Cerutti Mastodon site.

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