Contains supporting tables and figures.

Fig. A. Linear cuspal enamel thickness values in four hominin taxa. Fig. B. Long-period line periodicity in two A. anamensis individuals. Fig. C. Developmental plate used to assess tooth calcification in A. anamensis (KNM-KP 31712). Fig. D. Developmental plate used to assess tooth calcification in A. anamensis (KNM-KP 34725). Fig. E. Developmental plate used to assess tooth calcification in A. africanus (Sts 2). Fig. F. Developmental plate used to assess tooth calcification in A. africanus (Sts 24). Fig. G. Developmental plate used to assess tooth calcification in A. africanus (MLD 11/30). Fig. H. Developmental plate used to assess tooth calcification in P. robustus (SK 62). Fig. I. Developmental plate used to assess tooth calcification in P. robustus (TM 1536). Fig. J. Developmental plate used to assess tooth calcification in P. robustus (DNH 44). Fig. K. Developmental plate used to assess tooth calcification in P. robustus (DNH 47). Fig. L. Developmental plate used to assess tooth calcification in P. robustus (DNH 84). Fig. M. Developmental plate used to assess tooth calcification in P. robustus (DNH 107). Fig. N. Developmental plate used to assess tooth calcification in P. robustus (DNH 108). Fig. O. Developmental plate used to assess tooth calcification in early Homo (DNH 35). Fig. P. Developmental plate used to assess tooth calcification in early Homo (DNH 83). Fig. Q. Developmental plate used to assess tooth calcification in StW 151. Fig. R. Developmental plate used to assess tooth calcification in KB 5223. Fig. S. Ages at death predicted from modern human calcification standards compared to known- or histologically-derived ages. Fig. T. Recently erupted lower right first molar of DNH 107, a 4.8 year-old P. robustus individual from Drimolen. Table A. Long-period line periodicity (in days) for individuals in this study. Table B. Long-period line periodicity (in days) for fossil hominins, extant humans, and chimpanzees. Table C. Results of Mann-Whitney U test for comparisons of long-period line periodicity in P. robustus and A. africanus with fossil hominin taxa, extant humans, African apes, and previously published values. Table D. Cuspal enamel thickness values (in microns) for fossil hominins in this study. Table E. Age at death calculations for individual hominin specimens. Table F. Comparison of age at death estimates for two complete P. robustus mandibular dentitions. Table G. Histologically-determined initiation ages in Pliocene and early Pleistocene hominins.
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