Fig 1.
Distribution map and methodological setup.
Map with the distribution range of the Liberian chimpanzee population, the locality of the Taї National Park (Ivory Coast) and the distribution of Harmattan dust loads in those areas (A). The map and the Harmattan distribution was redrawn and adapted according to the data presented in Lesschen et al. [45]. Sampling procedure (B) for occlusal fingerprint analysis (macroscopic tooth wear) (C) and 3D surface texture analysis (microscopic tooth wear) (D) shown for the upper first molar (b = buccal, d = distal).
Fig 2.
Facet area and dip angles of phase II wear facets of the upper second molars compared between both chimpanzee populations.
Table 1.
Descriptive statistics for dip angles and areas for phase II wear facets.
Fig 3.
Factor analysis of wear facet 9 comparing the Liberian chimpanzee population to Taї chimpanzees from dry and rainy periods.
(A) upper molars; (B) lower molars; 3DST data for Taї chimpanzees taken from Schulz-Kornas et al. [13].
Table 2.
Post-hoc Tukey’s Test for the scores of factor 1 and 2 of the factor analysis comparing Liberian chimpanzees to Taï chimpanzees from dry and rainy period.
Fig 4.
Variation between sexes and populations shown for phase II dip angles and selected 3DST parameters.
Dip angle calculation on (A) upper and (B) lower phase II wear facets; (C) skewness of the height distribution (Ssk) on the upper facet 9; (D) density of peaks (Spd) on the lower facet 9. Strip charts indicate data median = horizontal line, interquartile range (IQR) = vertical line, and outlier (> 1.5*IQR) = x, significance levels are indicated by asterisks (* ≤ 0.05, ** < 0.01, *** < 0.001).