Fig. 3: Evidence for adulthood of the SOA-MM9 humerus.

a Three sites in a cortical section of the mid-posterior humeral shaft used for the histomorphological analyzes. ‘Middle field’ is a circle drawn in the outer one-third of the midsagittal line, and the ‘lateral field’ and ‘medial field’ are corresponding circles 3 mm apart from there. b Age-related histomorphometric values for SOA-MM9 and modern humans. The data from the three sites are plotted for all the modern human specimens, whereas the data for SOA-MM9 is from the lateral field only. The dotted lines are the means of the modern human adult subsample. See Supplementary Data 1 for the original data. c Cortical section of the posterior midshaft of SOA-MM9 observed by an ultra-high-definition microscope (VHX-7000, Keyence). The original image (left) and the same image colored for intact secondary osteons (red), fragmentary osteons (orange and yellow), and the intact inner surface (blue) (right). Note the dominance of secondary osteons around the exterior surface (downside of the images). Only one section (shown here) was produced to minimize the damage to the original specimen. d Lateral supracondylar ridge of SOA-MM9 and its CT section (the arrows). Note the weak but distinct development of the ridge as a slight eversion.