Extended Data Fig. 9: Comparative wear patterns.

a, The A. garhi BOU-VP-12/130 specimen has a very distinctive wear pattern with a continuous, broad longitudinal furrow from the maxillary canine to the molars, extending mesiodistally through the basin of each tooth, with differential wear on the lingual cusps (pers. obs., BV, LKD). This is different from the pattern on upper postcanine teeth in A. afarensis, A. africanus, P. robustus, and P. boisei, in which wear is more even across the breadth of the teeth (typically with a slight lingual-buccal wear gradient), and the cusps are ultimately reduced to the level of the central basin, producing a relatively flat occlusal profile. In A. garhi, the wear in the longitudinal furrow is sufficient to obliterate the central fissure, even in teeth with relatively unworn cusp apices (for example, contrast the P³s in the two specimens). We see no evidence of any wear pattern on the LD 760 assemblage that would indicate similarity to BOU-VP-12/130 (notably on the preserved fragmentary upper molar). The LD 760 wear pattern is more consistent with A. afarensis. b, In A. afarensis (A.L. 199-1), the canine lacks the large concave talon; the postcanine wear pattern is flatter with more wear on the cusps, ultimately approaching the level of the tooth’s central basin, which creates a flat rather than concave surface (note the visibility of the fissures on the first upper molar of A.L. 199-1 despite considerable cusp wear). Photos of BOU-VP-12/130 A. garhi holotype fossil by T. White; use courtesy of the Middle Awash research project. Scale in b is in centimetres.