By Jonah Ruddock
The Middle Pleistocene (also called the Chibanian), which took place from 774,000 to 129,000 years ago, is a complicated period in paleoanthropological history. Although it saw the rise of Homo sapiens in Africa and Homo neanderthalensis in Europe, along with many of their contemporaries, little is known about it, and to make matters worse, the terminology used is often vague and contradictory. This is why a team of researchers led by Dr. Mirjana Roksandic of the University of Winnipeg has proposed the reclassification of several hominin fossils and the naming of a new species. They are proposing that some of the fossils previously classified as Homo heidelbergensis or Homo rhodesiensis should instead be called Homo bodoensis, after a skull found in Bodo D’ar, Ethiopia. DNA tests have revealed that other Homo heidelbergensis bones are actually Neanderthals, so the team is arguing for the name H. heidelbergensis to be abandoned altogether, as it has been “poorly defined and used inconsistently.” H. rhodesiensis is also widely regarded as an inappropriate name, as it was given in honor of the infamous Cecil Rhodes.
“Taxonomic classification has a strong impact on conceptual understanding of evolution, and the taxonomic practice of reviving old names due to rules of precedence has sometimes played an important role in obfuscating our understanding of the complexity of Middle Pleistocene hominin evolution…By introducing a new, properly defined species, that recognizes and systematizes some of the observed variation, we hope to contribute a foundational piece from which palaeoanthropologists can build more robust explanatory models that better describe hominin evolution during the Middle Pleistocene,” stated Roksandic et al. in their paper, published in Evolutionary Anthropology last month.
Little is known about Homo bodoensis, but we do know they inhabited Africa and parts of Southeast Europe during the Middle Pleistocene. H. bodoensis is a direct ancestor of modern humans and split off from Eurasian hominins before that group split into Neanderthals and Denisovians. It is believed that our genus experienced some evolutionary changes during this time: the increase of brain size relative to body size, the transfer of cognitive functions from primitive parts of the brain to cerebral centers, a decrease in the size of teeth, and the differentiation of geographic groups. The shape of the skull discovered in Bodo D’ar, called Bodo 1, shows that H. bodoensis would probably look very similar to Homo erectus, but has a larger cranial capacity, one that lands somewhere in between Homo erectus and Homo sapiens.