Broken Hill cranium re-examined


April 07, 2020

In 1921, a well preserved cranium was found at a mining site called Broken Hill  in what is now Zambia, then southern Rhodesia. The cranium was estimated to be half a million years old and was given a new species name, Homo rhodesiensis. A paper in the journal nature last week reevaluated the dating and has reset the date add 300,000 years and reinforced the attribution by some scholars to H. heidelbergensis.

The paper, authored by  Rainer et al. Also casts doubt on the naming of fossils found that Atapuerca Spain  and given the binomial Homo ancessor, instead of incorporating the Atapuerca fossilswithin  H. heidelbergensis as well.

The abstract of this paper, published on April 1, reads as follows:
The cranium from Broken Hill (Kabwe) was recovered from cave deposits in 1921, during metal ore mining in what is now Zambia1. It is one of the best-preserved skulls of a fossil hominin, and was initially designated as the type specimen of Homo rhodesiensis, but recently it has often been included in the taxon Homo heidelbergensis2,3,4. However, the original site has since been completely quarried away, and—although the cranium is often estimated to be around 500 thousand years old5,6,7—its unsystematic recovery impedes its accurate dating and placement in human evolution. Here we carried out analyses directly on the skull and found a best age estimate of 299 ± 25 thousand years (mean ± 2?). The result suggests that later Middle Pleistocene Africa contained multiple contemporaneous hominin lineages (that is, Homo sapiens8,9, H. heidelbergensis/H. rhodesiensis and Homo naledi10,11), similar to Eurasia, where Homo neanderthalensis, the Denisovans, Homo floresiensis, Homo luzonensis and perhaps also Homo heidelbergensis and Homo erectus12 were found contemporaneously. The age estimate also raises further questions about the mode of evolution of H. sapiens in Africa and whether H. heidelbergensis/H. rhodesiensis was a direct ancestor of our species13,14.

Read the full Nature paper.