Also in the series of papers released Tuesday in the journal eLife is the announcement of a new chamber within the Rising Star cave where the hominin species was first found. It too contains a collection of H. naledi bones, including at least three individuals and one “remarkably complete” specimen with a nearly intact skull.
While the dating is robust, the presence of such a primitive-looking hominin species so late in our history is perplexing. In addition to an upper body more suited for tree-dwelling, H. naledi had tiny brains, smaller even than a chimpanzee, which would have left them at a disadvantage when competing with the more intelligent hominin species in the same area around that time. It’s not even known if they could use tools, although it’s certainly a possibility.
One hint at their capabilities comes from the very fact that they were found in the cave. The Dinaledi chamber where the first bones were found and the Lesedi chamber newly described today both lie down narrow, tortuous passages that only the slimmest of adults can reach. Both rooms lie within an area of complete darkness as well. The researchers were able to rule out falls, wild animals and natural causes as possible reasons for the bones’ presence, indicating that they were likely placed there by H. naledi themselves at a significant effort. Hawks and Berger hold that such a purposeful placement of the dead hints at the kind of burial rituals only seen in more advanced hominins.
Conclusion: Not that the researchers would draw it directly: We are still looking for that missing link.
New free papers: New fossil remains of Homo naledi from the Lesedi Chamber, South Africa:
The Rising Star cave system has produced abundant fossil hominin remains within the Dinaledi Chamber, representing a minimum of 15 individuals attributed to Homo naledi. Further exploration led to the discovery of hominin material, now comprising 131 hominin specimens, within a second chamber, the Lesedi Chamber. The Lesedi Chamber is far separated from the Dinaledi Chamber within the Rising Star cave system, and represents a second depositional context for hominin remains. In each of three collection areas within the Lesedi Chamber, diagnostic skeletal material allows a clear attribution to H. naledi. Both adult and immature material is present. The hominin remains represent at least three individuals based upon duplication of elements, but more individuals are likely present based upon the spatial context. The most significant specimen is the near-complete cranium of a large individual, designated LES1, with an endocranial volume of approximately 610 ml and associated postcranial remains. The Lesedi Chamber skeletal sample extends our knowledge of the morphology and variation of H. naledi, and evidence of H. naledi from both recovery localities shows a consistent pattern of differentiation from other hominin species.
Homo naledi and Pleistocene hominin evolution in subequatorial Africa:
New discoveries and dating of fossil remains from the Rising Star cave system, Cradle of Humankind, South Africa, have strong implications for our understanding of Pleistocene human evolution in Africa. Direct dating of Homo naledi fossils from the Dinaledi Chamber (Berger et al., 2015) shows that they were deposited between about 236 ka and 335 ka (Dirks et al., 2017), placing H. naledi in the later Middle Pleistocene. Hawks and colleagues (Hawks et al., 2017) report the discovery of a second chamber within the Rising Star system (Dirks et al., 2015) that contains H. naledi remains. Previously, only large-brained modern humans or their close relatives had been demonstrated to exist at this late time in Africa, but the fossil evidence for any hominins in subequatorial Africa was very sparse. It is now evident that a diversity of hominin lineages existed in this region, with some divergent lineages contributing DNA to living humans and at least H. naledi representing a survivor from the earliest stages of diversification within Homo. The existence of a diverse array of hominins in subequatorial comports with our present knowledge of diversity across other savanna-adapted species, as well as with palaeoclimate and paleoenvironmental data. H. naledi casts the fossil and archaeological records into a new light, as we cannot exclude that this lineage was responsible for the production of Acheulean or Middle Stone Age tool industries.
See also: Official paper on Homo naledi published… yes they’re recent, and now everything’s a big mess
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