June 2026: publication Peer Community in Paleontology
Taxonomic assignments for the 3.4 Ma to 1.1 Ma hominin postcanine teeth from 1 the Usno and Shungura Formations, Lower OmoValley, Ethiopia
Sediments of the Usno Formation and the Shungura Formation date from ca. 3.75 Ma to 1.09 Ma, during which time the genus Homo appeared, Australopithecus disappeared, and the eastern African robust hominins did both. We performed an in-depth analysis of size, shape, and morphology of 116 Omo permanent postcanine dental specimens to gain more insight to this evolutionary history. These fossils were recovered from two research programs: InternationalOmoResearch Expedition (IORE, 1967–1976) and the more recentOmoGroup Research Expedition (OGRE, since 2006). Here, we present a re-analysis of the IORE materials combined with an initial description of the OGRE collections. First, we compared linear dimensions against a comparative dataset of 820 teeth from 367 specimens representing 10 hominin taxa from eastern Africa. We then developed a linear discriminant function to predict the most-likely taxon for the Omo specimens based on the crown dimensions. We also ran cluster analyses on morphological scores and 2-dimensional cusp areas from the Omo sample to test whether these statistical clusters align with the taxa predicted by the discriminant function analysis. We found that variation in morphological scores does not align well with the taxonomic groups predicted from linear data. We also developed a checklist
References
Hlusko L. J., Guy F., Modesto-Mata M., Martínez de Pinillos M., Brasil M. F., Towle I., Thiebaut A., Boisserie J.-R. 2026. Taxonomic assignments for the 3.4 Ma to 1.1 Ma hominin postcanine teeth from the Usno and Shungura Formations, Lower Omo Valley, Ethiopia. osf.io/preprints/paleorxiv/g7kfx_v8, peer-reviewed and recommended by Peer Community In Paleontology 100360 – https://doi.org/10.31233/osf.io/g7kfx_v7