摘要：Homo naledi skeletal material described from the Dinaledi Chamber, Rising Star System, in the Cradle of Humankind,
South Africa, includes upper limb material with remarkably ape-like morphology occurring in the context
of a distinctly modern human-like lower limb, foot, and hand. Here we describe upper limb specimens from a
new fossil hominin site within the Rising Star System, the Lesedi Chamber (Site U.W. 102), including an intact
clavicle and a well-preserved proximal humerus and proximal ulna. Craniodental remains, in association with the
postcranial elements described here, have been attributed to H. naledi. The upper limb material from the Lesedi
Chamber is gracile and resembles the upper limb material from the Dinaledi Chamber in overall morphology.
The primitive humeral morphology of the Dinaledi material is replicated within the Lesedi material. The fossils
from the Lesedi Chamber material also preserve additional humeral morphology not represented in the Dinaledi
Chamber, providing new information on humeral form in this species. Three-dimensional geometric morphometric
analysis of the Lesedi proximal humerus demonstrates affinities with the humeri of Pan and Australopithecus.
The complete clavicle from Lesedi is similarly primitive, supporting previous interpretations of the H. naledi
shoulder as being more superiorly positioned than modern humans, and closer to the hypothesized australopith
condition. The ulna is gracile, with a mediolaterally narrow olecranon process and anterior-facing trochlear notch
similar to the derived state suggested for other fossil hominins. These new findings support the interpretation of
overhead reaching and climbing behaviors having continued relevance in the locomotor repertoire of Homo naledi
and provide a clearer picture of the upper limb morphology of this species.
