SUPPLEMENTARY INFORMATION

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1 doi: /nature16448 Supplementary Table 1. Summary of the stone artefact distributions, T2 and T4. T2 Age and context T4 Type <103 kyr, topsoil (A 1) <103 kyr, conglomerate (A 2-A 4) kyr, conglomerate (A 5-A 7) Total topsoil (Z) colluvium (X 1-X 3) >156 kyr silt (E 2) Total Core Flake Modified flake Total Supplementary Table 2. Summary of the stone artefact sizes, T2, kyr (A 5 -A 7 ); and T4, >156 kyr (E 2 ). Type Artefact size (mm) Artefact weight (g) Core scar size (mm) Average Max. Average Max. Average Max. T2 (n=10) Core ± (n=10) ± ± T2 (n=55) Flake ± (n=55) ± T4 (n=4) Flake (n=4)

2 Supplementary Table 3. Uranium-series ages of fossil tooth and bone samples based on sequential laser spot U-Th analyses. Sample No Lab. No. Locality; Depth below ground surface element TLP10-F1a 2947 T4; 3.3 m Celebochoerus lower canine TLP10-F1b 2948 T4; 3.3 m Celebochoerus lower canine TLP10-F T4; sieve, m TLP10-F T4; sieve, m TLP10-F T4; sieve, m DAD-Fitting 2σ age range (kyr) 161 ± 15 >255 Celebochoerus p4 >600 Celebochoerus M3 sin Celebochoerus M3 dex 214 ± 24 >361 TLP10-F T4; sieve bone fragment 230 ± 38 TLP10-F T4; 3.6 m Celebochoerus rib fragment TLP10-F T4; sieve, m TLP10-F T4; sieve, m Celebochoerus I1 sin Celebochoerus molar fragment >353 > ±

3 Supplementary Table 4. Sample burial depths, dosimetry data, equivalent dose (D e ) values and age estimates for the Talepu samples. Sample code Depth * (m) Grain diameter (µm) Water content (%) Gamma dose rate External beta Cosmic ray Internal Total D e (Gy) Age (kyr) T2 Upper Trench TUT-OSL ± 5 (19.8) 1.56 ± ± ± ± ± ± 42 (8) 103 ± 9 TUT-OSL ± 5 (20.9) 1.60 ± ± ± ± ± ± 45 (10) 126 ± 11 TUT-OSL ± 5 (13.9) 1.30 ± ± ± ± ± ± 48 (12) 141 ± 12 TUT-OSL ± 5 (10.6) 1.30 ± ± ± ± ± ± 84 (13) 156 ± 19 T4 Lower Trench TLT-OSL ± 5 (29.8) 1.49 ± ± ± ± ± 0.14 >820 (8) >195 * Depth below local ground surface. Values used for and age calculations, with measured (field) water contents shown in parentheses. Assuming K and Rb concentrations of 13 ± 1% and 400 ± 100 μg/g, respectively. Weighted mean ± standard error of the individual single-aliquot D e values for the sensitivity-corrected MET-pIRIR 250 C signal, calculated using the central age model. The number of aliquots is shown in parentheses. For the TUT samples, residual doses of Gy (obtained from bleached aliquots of each sample) have been subtracted. The minimum D e value listed for TLT-OSL6 corresponds to 90% of the saturation level (i.e., 2.3D 0 ) of the typical 250 C MET-pIRIR doseresponse curve (see text for discussion). One of the 14 measured aliquots of sample TUT-OSL9 was rejected from the data set, as the natural signal was in saturation. Total uncertainty (1σ) includes the propagated random errors and a 2% systematic error to allow for any possible bias associated with calibration of the laboratory beta source. Only a minimum age could be determined for TLT-OSL6 and the age estimates for the TUT samples could also be viewed conservatively as minimum ages (see discussion in Supplementary section 3.4). 3

4 Supplementary Table 5. High-resolution gamma spectrometry (HRGS) activities and the corresponding s and ages for the Talepu samples. Sample code TUT- OSL1 TUT- OSL2 TUT- OSL3 TUT- OSL9 TLT- OSL6 238 U 226 Ra 210 Pb 228 Ra 228 Th 40 K Scenario * External beta Gamma dose rate Total dose rate 57 ± ± ± ± ± ± 31 A 2.84 ± ± ± ± 9 Age (kyr) B 2.91 ± ± ± ± 9 41 ± ± ± ± ± ± 24 A 2.18 ± ± ± ± 12 B 2.26 ± ± ± ± ± ± ± ± ± ± 26 A 2.66 ± ± ± ± 10 B 2.26 ± ± ± ± ± ± ± ± ± ± 34 A 2.92 ± ± ± ± 18 B 2.94 ± ± ± ± ± ± ± ± ± ± 23 A 2.06 ± ± ± 0.19 >185 B 2.07 ± ± ± 0.19 >184 * Scenario A: External beta and gamma s calculated using the measured present-day activities of 238 U, 226 Ra and 210 Pb (i.e., the values as listed) and adjusted for beta-dose attenuation and a sample water content of 20 ± 5%, to facilitate direct comparison with the data in Supplementary Table 4. Scenario B: External beta and gamma s calculated assuming that the 226 Ra and 210 Pb deficits (or excesses in the case of TUT-OSL3) occurred recently, and that the 238 U chain was in secular equilibrium for almost the entire period of sample burial. Under this assumption, the 238 U activities are used also for 226 Ra and 210 Pb, with adjustments for beta-dose attenuation and water content (20 ± 5%). Consists of the external beta and gamma s shown in this table, plus the cosmic-ray and internal beta s listed in Supplementary Table

5 Supplementary Table 6. The MET-pIRIR single-aliquot regenerative-dose protocol used in this study. Step Treatment Observed 1 Give regenerative dose, D i * 2 Preheat at 320 C for 60 s 3 IRSL measurement at 50 C for 100 s L x(50) 4 IRSL measurement at 100 C for 100 s L x(100) 5 IRSL measurement at 150 C for 100 s L x(150) 6 IRSL measurement at 200 C for 100 s L x(200) 7 IRSL measurement at 250 C for 100 s L x(250) 8 Give test dose, D t (64 Gy) 9 Preheat at 320 C for 60 s 10 IRSL measurement at 50 C for 100 s T x(50) 11 IRSL measurement at 100 C for 100 s T x(100) 12 IRSL measurement at 150 C for 100 s T x(150) 13 IRSL measurement at 200 C for 100 s T x(200) 14 IRSL measurement at 250 C for 100 s T x(250) 15 Solar simulator bleach, 2 hr 16 Return to step 1 * For the natural sample, the given dose is 0 Gy and the observed signals are L n and T n. The entire sequence is repeated for several regenerative doses, including a zero dose and a repeat regenerative dose. 5

6 Supplementary Table 7. Sample burial depths, mean magnetic directions, and statistical parameters for sampled levels from the T2 and T4 excavations. Excavation- Depth * (cm) Mean Declination Before demagnetization Mean Inclination Number of Mean samples R k α 95 Declination After demagnetization Mean Inclination R k α95 T T T T T T T T T T T T T T T T T T T T T T T T * Depth below local ground surface R is the vector resultant of the N site-mean Virtual Geomagnetic Poles 60 k is the precision parameter Confidence limit within two standard errors from the calculated mean

7 Supplementary Table 8. Listing of the alternating field state at which higher coercivity stable magnetization (ChRM) is reached, and the Mean Angular Deviation (MAD) values for individual sub-samples of each sampled level from the T2 and T4 excavations. Subsamples per sampled level ChRM state (mt) MAD Subsamples per sampled level ChRM state (mt) MAD Subsamples per sampled level ChRM state (mt) MAD Subsamples per sampled level T2-320S T T T T T T T2-510S T T T T2-650S T T T T2-750S T T T T T T T ChRM state (mt) MAD 7

8 Supplementary Table 9. Argon isotopic analyses of gas released by CO 2 laser fusion of single sanidine crystals from sample TAL TAL (J = ± ) LabID# 40 Ar ±1σ 39 Ar ±1σ 38 Ar ±1σ 37 Ar ±1σ Isotopic Abundances (mv) 36 Ar ±1σ % 40 Ar* Age (Myr) ±1σ 8

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