Inner structural organization of the distal humerus in Paranthropus and Homo

A distinct inner structural organization of the distal humerus differentiates Paranthropus from Homo, challenging previous classifications based solely on external morphology. Using non-invasive imaging techniques, researchers analyzed five fossil specimens—four from South Africa (TM 1517g, SK 24600, SKX 10924, SKX 34805) and one from Ethiopia (Gombore IB)—previously attributed to either Paranthropus or Homo. The study revealed two primary endostructural patterns: three specimens clustered together (TM 1517g, SKX 10924, SKX 34805), while Gombore IB, a robust Homo aff. erectus from Melka Kunture, aligned with modern human samples in cortical thickness distribution and trabecular organization. These findings highlight the heterogeneity between external morphology and internal structure, suggesting that SKX 34805's taxonomic status warrants further investigation.

Cazenave, M., Braga, J., Oettlé, A., Thackeray, J. F., de Beer, F., Hoffman, J., Endalamaw, M., Redae, B. E., Puymerail, L., & Macchiarelli, R. (2017). Inner structural organization of the distal humerus in Paranthropus and Homo. Comptes Rendus Palevol, 16(5-6), 521–532. https://doi.org/10.1016/j.crpv.2017.06.002