Two articles, one published in the journal “Nature” and one in the journal “Proceedings of the National Academy of Sciences” (PNAS), describe a research about the possible coexistence of different species of hominins in East Africa between 3.8 and 3.3 million years ago. In 2015 fossils found in Ethiopia were assigned to a new species called Australopithecus deyiremeda, which lived close to the species Australopithecus afarensis (photo ©Andrew), the one the famous specimen nicknamed Lucy belonged to.
The discovery of fossil bones of Lucy represented a milestone in the field of paleoanthropology. The existence of Australopithecus afarensis proved that hominins dated back to more than 3 million years ago and initially looked like they could be the species ancestor of the genus homo. However, over the following decades things have become more complicated.
In 1995, in Chad a new hominin was found that was called Australopithecus Bahrelghazali with an age between 3 and 3.5 million years. In 1999, in Kenya another hominin was found that showed such differences from australopithecines that it was attributed to a new genus and named kenyanthropus platyops with an age between 3.2 and 3.5 million years.
Australopithecus deyiremeda is just the latest species discovered so far, if it gets confirmed officially. It was discovered by a team led by paleontologist Yohannes Haile-Selassie, curator of physical anthropology at The Cleveland Museum of Natural History, USA, and lead author of the articles on this research. So far they found a part of a jaw, two jaws and some other fragments dated between 3.3 and 3.5 million years ago in the Afar region, Ethiopia.
If it were confirmed that the fossils identified as Australopithecus deyiremeda actually are a new species and not Australopithecus afarensis specimens, they’d still have to establish the various relations among the various species. Questions would also remain regarding the coexistence of various species of hominins related in various ways.
In recent years we’ve been discovering more and more that there are various hybrids among species of the homo genus so one wonders how many times the populations of the various hominins in East Africa may have been cross-bred. In that case, the identification of the fossils species may become more complex.
It’s one of the cases in which paleoanthropologists have to work with few bones and very little else. Even the most advanced genetic techniques can’t extract DNA fragments from bones that are so old so we can’t hope for any answers from that type of analysis.
In these cases, the hope is to find new fossils to reconstruct a kind of big jigsaw puzzle of the hominin lineage. Each new piece can help understand how many hominin species lived in East Africa during the middle Pliocene, their relations and if there was a co-existence between different species.
