Figure 7. Phalangeal curvature in H. naledi.

Above, proximal and IPs of the Hand 1 (a) second, (b) third (c) fourth and (d) fifth ray in lateral view (all to scale). Below, box-and-whisker plots of curvature in H. naledi (e) intermediate phalanges (n=14) and (f) proximal phalanges (n=11), quantified as the first polynomial coefficient (A) of the polynomial functions (y=Ax²+Bx+C) representing longitudinal shaft curvature of the dorsal surface. Vertical line represents the median value, boxes show the interquartile range and whiskers extend to the highest and lowest values of each taxon, excluding outliers (dots). The H. naledi sample is shown in red and extant taxa that are not statistically distinct from this sample (P≤0.05 based on one-way analysis of variance with Bonferroni correction) are shown in blue. ‘SKX Mem. 1' and ‘SKX Mem. 3' refer to the Swartkans phalanx sample from Members 1 and 3, respectively, that can be attributed to either A. robustus or early Homo. ‘UW 101-1635' is a juvenile H. naledi proximal phalanx. H. naledi is unusual compared with most other hominins in having both strongly curved proximal and intermediate phalanges.