Over 60 years ago, stone tools and remains of megafauna were discovered on the Southeast Asian islands of Flores, Sulawesi and Luzon, and a Middle Pleistocene colonization by Homo erectus was initially proposed to have occurred on these islands1,2,3,4. However, until the discovery of Homo floresiensis in 2003, claims of the presence of archaic hominins on Wallacean islands were hypothetical owing to the absence of in situ fossils and/or stone artefacts that were excavated from well-documented stratigraphic contexts, or because secure numerical dating methods of these sites were lacking. As a consequence, these claims were generally treated with scepticism5. Here we describe the results of recent excavations at Kalinga in the Cagayan Valley of northern Luzon in the Philippines that have yielded 57 stone tools associated with an almost-complete disarticulated skeleton of Rhinoceros philippinensis, which shows clear signs of butchery, together with other fossil fauna remains attributed to stegodon, Philippine brown deer, freshwater turtle and monitor lizard. All finds originate from a clay-rich bone bed that was dated to between 777 and 631 thousand years ago using electron-spin resonance methods that were applied to tooth enamel and fluvial quartz. This evidence pushes back the proven period of colonization6 of the Philippines by hundreds of thousands of years, and furthermore suggests that early overseas dispersal in Island South East Asia by premodern hominins took place several times during the Early and Middle Pleistocene stages1,2,3,4. The Philippines therefore may have had a central role in southward movements into Wallacea, not only of Pleistocene megafauna7, but also of archaic hominins.
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J. Barns and A. Labrador provided support for this research as well as G. Concepcion and M. dela Cruz Jr. The Kalinga excavation project was funded by the French Department for Foreign Affairs (Project MARCHE, to T.I.), The National Museum of The Philippines (to C.J.-o. and M.C.R.), The University of the Philippines Diliman Research Grant of the Office of Vice President for Academic Affairs (to T.I.) and the European Social Fund (Project ISOLARIO, NSRF Thalis-UOA, to G.L.). T.I. also received funding from a National Geographic Global Exploration grant (HJ-035R-17), from the French Centre National de la Recherche Scientifique (GDRi PalBiodivASE with Valéry Zeitoun), from Sorbonne Universités (Project MH@SU TAPHO), from the Société des Amis du Musée de l’Homme and from the LabEx BCDiv. G.D.v.d.B. received funding from an Australian Research Council (ARC) Future fellowship (FT100100384). J.d.V. received funding from the Quaternary and Prehistory Erasmus Mundus Program. Additional funding was provided by the Embassy of France to the Philippines and by the Rizal Municipality. M.G.C. received funding from CERCA Programme/Generalitat de Catalunya. We thank S. Hayes for her feedback on the manuscript; M.-M. Blanc-Valleron for providing access to the X-ray diffractometer; A. Ledoze, S. Puaud, V. Scao, S. Baillon, H. Guillou, J. Marteau, M. Bigerelle, R. Deltombe, D. Borshneck and F. Demory for their valuable help in the laboratory analyses.Reviewer information
Nature thanks M. Duval, J. Kappelman, R. Potts and the other anonymous reviewer(s) for their contribution to the peer review of this work.
Extended data figures and tables
a, Detailed stratigraphic drawing of trench H also showing the east wall of the S quadrant of the main excavation. The sedimentary patterns are the same as in Fig. 1. Representative logarithmic grain-size diagrams are shown for samples from each sedimentary unit. b, Detailed stratigraphic drawing of the main excavation walls. c, Overview towards the northwest of the quadrants N and NW of the main excavation in 2015. The concentration of faunal remains and stone tools lying at the base of unit F is exposed, just above the eastward sloping erosional contact with unit A. d, Detailed view of quadrant NW showing the position of a flake lying next to the rhinoceros left femur. e, Detail of quadrant N showing the piece of waterlogged wood fragment (yellow outline) recovered near a rhinoceros rib extremity (blue outline). f, Detail of quadrant NE showing the tektite recovered in unit F along with the faunal and lithic remains.
a, Drawing showing the preservation of the rhinoceros and position of the taphonomical marks. A total of 97 fragments of ribs of all sizes have been recovered and not all of them could be clearly positioned on the skeleton. We estimate that about 75% of the skeleton has been recovered. b, Fibula of Varanus salvator. c, Radius of a Cervidae. d, Molar of Cervus cf. mariannus. e, Molar fragment of Stegodon cf. luzonensis.
The model shows the contact surface topography between unit A and unit F and the vertical projections (black squares) of the archaeological materials (coloured points) on this surface. The model was produced by interpolation through a kriging method from 37 three-dimensional coordinates recorded in the main excavation with a total station on the erosional surface that cuts down into unit A. This surface of contact corresponds to an erosional channel cutting down into the sandy unit A. All the material has been recovered lying across the base of the clay-rich unit F along this channel, between 0.7 m and 1.3 m deep.
Quartz corresponds to the bipyramidal quartz crystals, some of which are visible to the naked eye. Bipyramidal quartz, albite, hornblende, nontronite and saponite all have a volcanic origin. Albite is a plagioclase feldspar frequent in pegmatites. Hornblende is a common silicate mineral in igneous and metamorphic rocks. Nontronite is an iron-rich smectite type of clay, which can be produced by hydrothermal alteration. Similarly, the smectite mineral saponite results from alteration of volcanic glass. The mineral composition of unit F supports the interpretation as a mudflow set in a volcanic environment. CPS, counts per second; Cu K-α corresponds to the wavelength.
Extended Data Figure 5 40Ar/39Ar fusion ages of single potassium plagioclase crystals for samples from unit A and unit G.
a, b, Probability diagrams (a) are correlated to the related inverse isochrones (b). Individual ages in a are ±1σ.
Extended Data Figure 6 Measurements of dose rates and calculation of equivalent dose to compute the ESR ages from quartz crystals and tooth enamel.
a, Al and Ti centre ESR spectra of natural and bleached aliquots for unit A quartz showing that the Al signal is not completely reset, although it is not measurable because it is extremely weak and concealed by noise. b, ESR dose–response curve obtained for the rhinoceros tooth (archaeological number: II-2014-J1-095; sample code: CGY1501). The equivalent dose (De) was extrapolated using a single saturating exponential function (Origin Microcal software) following the recommendations of Duval and Grün31 (De < 500 Gy, therefore Dmax < 5,000 Gy for this sample). c–f, ESR dose–response curves, for the aluminium (Al) and titanium–lithium (Ti-Li) centres of layers G1 and A4. b–f, The vertical bars indicate the standard deviation around the mean for each measurement. The red curve is the dose–response curve. The blue curves indicate the 95% confidence interval of the dose–response curve.
Extended Data Figure 7 Progressive demagnetization curves, equal area projection stereoplots and Zijderveld diagrams for the six analysed specimens from Layer G2.
a–f, Each panel shows the progressive demagnetization curves (bottom left), equal area projection stereoplots (top left) and Zijderveld diagrams (right). Open circles in the Zijderveld diagrams represent the inclination whereas closed circles represent declination. Open and closed circles in the equal area projection (stereoplot) represent the upper and lower hemisphere, respectively. a–e, Specimens were treated by alternating field demagnetization. f, Specimen HT-1E was treated by thermal demagnetization. g, h, Equal area projections of the mean chemical remanent magnetization (ChRM) directions of all analysed specimens before (g) and after (h) demagnetization. Solid squares represent the upper hemisphere. The black cross indicates the mean ChRM direction of the six specimens combined, surrounded by the α95 circle. The red cross represents the present-day magnetic direction.
Extended Data Figure 8 Analysis of the Kalinga tektite recovered from the archaeological layer unit F.
a, Picture of the tektite. b, Micro-X-ray fluorescence (µXRF) spectra (un-indexed peaks correspond to the Rh source) showing its composition. c, Comparison of the Kalinga tektite glass composition through µXRF to an australasite tektite from China measured in the same conditions (red squares) and an average australasite composition (blue diamonds)32.