NEW DELHI: A new human ancestor species which roamed the Afar region of Ethiopia 3.3 to 3.5 million years ago has been discovered by an international team of scientists. Named Australopithecus deyiremeda, this new species joins ‘Lucy’ the famous hominin that is known to have lived in the same region. The discovery is described in the science journal Nature. Lucy’s species (called Australopithecus afarensis ) lived from 2.9 million years ago to 3.8 million years ago, overlapping in time with the new species. The new discovery is the most conclusive evidence that more than one closely related human ancestor species lived in the same period, more than 3 million years ago. The species name “deyiremeda” (day-ihreme-dah) means “close relative” in the language spoken by the Afar people, according to the Cleveland Museum of Natural History. Australopithecus deyiremeda differs from Lucy’s species in terms of the shape and size of its thick-enameled teeth and the robust architecture of its lower jaws. The anterior teeth are also relatively small indicating that it probably had a different diet.
“The new species is yet another confirmation that Lucy’s species, Australopithecus afarensis, was not the only potential human ancestor species that roamed in what is now the Afar region of Ethiopia during the middle Pliocene,” said lead author Dr Yohannes Haile-Selassie of the Cleveland Museum. “Current fossil evidence from the Woranso-Mille study area clearly shows that there were at least two, if not three, early human species living at the same time and in close geographic proximity.”
“This new species from Ethiopia takes the ongoing debate on early hominin diversity to another level,” said Haile-Selassie. “Some of our colleagues are going to be skeptical about this new species, which is not unusual. However, I think it is time that we look into the earlier phases of our evolution with an open mind and carefully examine the currently available fossil evidence rather than immediately dismissing the fossils that do not fit our long-held hypotheses,” said Haile-Selassie.
Scientists have long argued that there was only one pre-human species at any given time between 3 and 4 million years ago, subsequently giving rise to another new species through time. This was what the fossil record appeared to indicate until the end of the 20th century. However, the naming of Australopithecus bahrelghazali from Chad and Kenyanthropus platyops from Kenya, both from the same time period as Lucy’s species, challenged this long-held idea. Although a number of researchers were skeptical about the validity of these species, the announcement by Haile-Selassie of the 3.4 million-year-old Burtele partial foot in 2012 cleared some of the skepticism on the likelihood of multiple early hominin species in the 3 to 4 million-year range.
This discovery has important implications for our understanding of early hominin ecology. It also raises significant questions, such as how multiple early hominins living at the same time and geographic area might have used the shared landscape and available resources.