Table 2. 2D enamel thickness variables assessed in TD6 maxillary and mandibular molars and compared with extinct and extant specimens/populations.
Individual values and mean and range (in bold) are given for TD6 molar data. Mean and range are given for the comparative sample when having more than two specimens. Individual values are given for the rest of comparative sample.
| Specimens | Tooth | N | Mean & Range | c (mm2) | b (mm2) | e (mm) | b/a (%) | AET (mm) | RET |
| UM1 | |||||||||
| ATD6-10 | 1 | 20.52 | 43.04 | 19.24 | 67.72 | 1.07 | 16.26 | ||
| ATD6-11 | 1 | 24.23 | 43.17 | 20.06 | 64.05 | 1.21 | 18.38 | ||
| ATD6-69 | 1 | 22.72 | 37.33 | 20.84 | 62.16 | 1.09 | 17.84 | ||
| ATD6-103 | 1 | 24.56 | 47.66 | 22.14 | 65.99 | 1.11 | 16.07 | ||
| Mean | 23.01 | 42.80 | 20.57 | 64.98 | 1.12 | 17.14 | |||
| Range | 20.52–24.56 | 37.33–47.66 | 19.24–22.14 | 62.16–67.72 | 1.07–1.21 | 16.07–18.38 | |||
| HER | 1 | 28.90 | 46.60 | 22.20 | 61.72 | 1.30 | 19.07 | ||
| EMPH | 1 | 23.25 | 40.99 | 21.49 | 63.81 | 1.08 | 16.90 | ||
| NEA | 5 | Mean | 22.98 | 43.94 | 22.36 | 65.68 | 1.03 | 15.50 | |
| Range | 21.03–28.0 | 37.19–49.75 | 21.08–23.45 | 63.87–68.03 | 0.93–1.19 | 13.79–16.92 | |||
| MH | 37 | Mean | 42.87 | 25.18 | 20.64 | 62.85 | 1.22 | 18.75 | |
| Range | 32.46–59.44 | 17.66–24.11 | 57.16–68.98 | 0.98–1.50 | 13.95–23.86 | ||||
| UM2 | |||||||||
| ATD6-12 | 1 | 23.99 | 39.05 | 18.95 | 61.94 | 1.27 | 20.26 | ||
| ATD6-69 | 1 | 29.33 | 42.83 | 19.30 | 59.35 | 1.52 | 23.22 | ||
| Mean | 26.66 | 40.94 | 19.13 | 60.65 | 1.39 | 21.74 | |||
| Range | 23.99–29.33 | 39.05–42.83 | 18.95–19.30 | 59.35–61.94 | 1.27–1.52 | 20.26–23.22 | |||
| HER | 1 | 33.73 | 57.70 | 22.86 | 63.11 | 1.48 | 19.42 | ||
| HER | 1 | 1.51 | 23.52 | ||||||
| EMPH | 1 | 25.79 | 48.99 | 21.51 | 65.51 | 1.20 | 17.13 | ||
| NAH | 1 | 32.02 | 56.78 | 22.59 | 63.94 | 1.42 | 18.81 | ||
| NEA | 7 | Mean | 25.96 | 43.41 | 21.40 | 62.36 | 1.21 | 18.59 | |
| Range | 22.72–29.05 | 36.74–58.72 | 19.85–24.22 | 58.77–66.90 | 1.12–1.29 | 15.65–21.41 | |||
| FHS | 1 | 25.97 | 43.63 | 19.82 | 62.69 | 1.31 | 19.84 | ||
| MH | 25 | Mean | 42.76 | 28.61 | 20.49 | 60.05 | 1.40 | 21.59 | |
| Range | 30.12–65.71 | 18.22–24.83 | 53.80–66.45 | 1.13–1.76 | 16.49–28.03 | ||||
| Specimens | Tooth | N | Mean & Range | c (mm2) | b (mm2) | e (mm) | b/a (%) | AET (mm) | RET |
| LM1 | |||||||||
| ATD6-5 | 1 | 25.02 | 35.52 | 18.16 | 58.67 | 1.38 | 23.12 | ||
| ATD6-94 | 1 | 23.12 | 44.67 | 20.47 | 65.89 | 1.13 | 16.90 | ||
| ATD6-112 | 1 | 21.98 | 27.35 | 18.82 | 55.44 | 1.17 | 22.33 | ||
| ATD6-96 | 1 | 18.07 | 33.52 | 18.00 | 64.97 | 1.00 | 17.34 | ||
| Mean | 22.05 | 35.27 | 18.86 | 61.25 | 1.17 | 19.92 | |||
| Range | 18.07–25.02 | 27.35–44.67 | 18.00–20.47 | 55.44–65.89 | 1.00–1.38 | 16.90–23.12 | |||
| EAH | 1 | 18.60 | 38.20 | 18.60 | 67.25 | 1.00 | 16.18 | ||
| NEA | 12 | Mean | 21.12 | 40.44 | 21.07 | 65.62 | 1.00 | 15.88 | |
| Range | 16.82–23.81 | 33.38–45.42 | 17.65–23.25 | 60.48–69.27 | 0.92–1.18 | 13.76–20.45 | |||
| MH | 55 | Mean | 40.16 | 21.74 | 20.32 | 64.48 | 1.07 | 16.99 | |
| Range | 27.45–50.82 | 16.73–22.94 | 59.19–72.65 | 0.80–1.40 | 11.76–22.62 | ||||
| LM2 | |||||||||
| ATD6-5 | 1 | 17.40 | 33.74 | 16.97 | 65.98 | 1.03 | 17.65 | ||
| ATD6-113 | 1 | 21.32 | 33.22 | 17.47 | 60.91 | 1.22 | 21.17 | ||
| ATD6-144 | 1 | 22.98 | 25.43 | 16.72 | 52.53 | 1.37 | 27.25 | ||
| ATD6-96 | 1 | 16.34 | 25.14 | 16.03 | 60.61 | 1.02 | 20.33 | ||
| Mean | 19.51 | 29.38 | 16.80 | 60.01 | 1.16 | 21.60 | |||
| Range | 16.34–22.98 | 25.14–33.74 | 16.03–16.97 | 52.53–65.98 | 1.002–1.37 | 17.65–27.25 | |||
| NAH | 1 | 25.20 | 47.70 | 21.10 | 65.43 | 1.19 | 17.29 | ||
| HER | 4 | Mean | 23.18 | 33.65 | 18.23 | 59.03 | 1.27 | 22.15 | |
| Range | 21.2–23.4 | 30.60–41.30 | 17.40–20.20 | 56.04–59.54 | 1.19–1.37 | 18.56–24.93 | |||
| NEA | 8 | Mean | 20.97 | 42.73 | 20.49 | 67.13 | 1.02 | 15.66 | |
| Range | 17.1–22.53 | 33.85–47.56 | 17.78–22.89 | 65.27–67.95 | 0.94–1.14 | 14.2016.80 | |||
| MH | 45 | Mean | 34.33 | 22.05 | 18.52 | 60.78 | 1.19 | 20.51 | |
| Range | 23.75–42.24 | 15.22–21.60 | 53.21–67.80 | 0.94–1.55 | 14.85–27.66 | ||||
| LM3 | |||||||||
| ATD6-5 | 1 | 20.00 | 30.65 | 16.68 | 60.51 | 1.20 | 21.66 | ||
| ATD6-113 | 1 | 17.83 | 28.45 | 15.80 | 61.47 | 1.13 | 21.16 | ||
| ATD6-96 | 1 | 12.72 | 13.97 | 11.66 | 52.34 | 1.09 | 29.19 | ||
| Mean | 16.85 | 24.36 | 14.71 | 58.11 | 1.14 | 24.00 | |||
| Range | 12.72–20.00 | 13.97–30.65 | 11.66–16.68 | 52.33–61.47 | 1.09–1.20 | 29.19–21.16 | |||
| HER | 1 | 15.90 | 24.10 | 16.30 | 60.25 | 0.98 | 19.87 | ||
| EMPH | 1 | 1.27 | 21.60 | ||||||
| EMPH_BH | 1 | 15.22 | 27.48 | 16.26 | 64.36 | 0.94 | 17.86 | ||
| NEA | 9 | Mean | 19.28 | 36.71 | 18.99 | 65.45 | 1.01 | 16.80 | |
| Range | 16.70–24.84 | 30.58–48.02 | 17.56–20.93 | 63.34–69.83 | 0.91–1.16 | 14.29–18.86 | |||
| MH | 44 | Mean | 33.09 | 22.58 | 18.27 | 59.31 | 1.24 | 21.63 | |
| Range | 24.40–45.98 | 16.75–29.42 | 15.90–22.26 | 50.82–64.61 | 0.98–1.67 | 17.22–31.84 |
Upper molars. TD6: H. antecessor from Gran Dolina (original data). HER: H. erectus (Sangiran_M1, Zanolli [54]; China_M2, Smith et al. [10]; Xing et al. [67]). EMPH: European Middle Pleistocene Homo (Steinheim_M1, Smith et al. [10]). NAH: North African Homo (Thomas Quarry_M2, Smith et al. [10]). NEA: Neanderthals (Olejniczak et al. [8]). FHS: fossil H. sapiens (Qafzeh_M2, Smith et al. [10]). MH: modern humans (Smith et al. [9, 10] and pers. comm.). Lower molars TD6: H. antecessor from Gran Dolina (original data). EAH: East African Homo (Eritrea_M1, Zanolli et al. [56]). NAH: North African Homo (Tighenif_M2, Zanolli and Mazurier [11]). HER: H. erectus (Sangiran_M2 & M3; Zanolli [54]). EMPH: European Middle Pleistocene Homo (Mauer_M3, Smith et al. [10]. EMPH_BH: European Middle Pleistocene Homo (Mala Balanica_M3, Skinner et al. [24]). NEA: Neanderthals (Olejniczak et al. [8]). MH: modern humans (Smith et al. [9, 10] and Smith pers. comm.).