Upper and lower jaw fossils recovered from the Woranso-Mille area of the Afar region of Ethiopia have been assigned to the new species Australopithecus deyiremeda. This hominin lived alongside the famous “Lucy’s” species, Australopithecus afarensis. The species will be described in the May 28, 2015 issue of the international scientific journal Nature.
Lucy’s species lived from 2.9 million years ago to 3.8 million years ago, overlapping in time with the new species Australopithecus deyiremeda. The new species is the most conclusive evidence for the contemporaneous presence of more than one closely related early human ancestor species prior to 3 million years ago. The species name “deyiremeda” (day-ihreme-dah) means “close relative” in the language spoken by the Afar people.
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 and Woranso-Mille project team leader Dr. Yohannes Haile-Selassie, curator of physical anthropology at The Cleveland Museum of Natural History. “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.”
“The age of the new fossils is very well constrained by the regional geology, radiometric dating, and new paleomagnetic data,” said co-author Dr. Beverly Saylor of Case Western Reserve University. The combined evidence from radiometric, paleomagnetic, and depositional rate analyses yields estimated minimum and maximum ages of 3.3 and 3.5 million years.
“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.
The Burtele partial fossil foot did not belong to a member of Lucy’s species. However, despite the similarity in geological age and close geographic proximity, the researchers have not assigned the partial foot to the new species due to lack of clear association. Regardless, the new species Australopithecus deyiremeda incontrovertibly confirms that multiple species did indeed co-exist during this time period.
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.
Discovery of Australopithecus deyiremeda:
The holotype (type specimen) of Australopithecus deyiremeda is an upper jaw with teeth discovered on March 4, 2011, on top of a silty clay surface at one of the Burtele localities. The paratype lower jaws were also surface discoveries found on March 4 and 5, 2011, at the same locality as the holotype and another nearby locality called Waytaleyta. The holotype upper jaw was found in one piece (except for one of the teeth which was found nearby), whereas the mandible was recovered in two halves that were found about two meters apart from each other. The other mandible was found about 2 kilometers east of where the Burtele specimens were found.
Location of the Discovery:
The fossil specimens were found in the Woranso-Mille Paleontological Project study area located in the central Afar region of Ethiopia about 325 miles (520 kilometers) northeast of the capital Addis Ababa and 22 miles (35 kilometers) north of Hadar (“Lucy’s” site). Burtele and Waytaleyta are local names for the areas where the holotype and paratypes were found and they are located in the Mille district, Zone 1 of the Afar Regional State.
The Woranso-Mille Project:
The Woranso-Mille Paleontological project conducts field and laboratory work in Ethiopia every year. This multidisciplinary project is led by Dr. Yohannes Haile-Selassie of The Cleveland Museum of Natural History. Additional co-authors of this research include: Dr. Luis Gibert of University of Barcelona (Spain), Dr. Stephanie Melillo of the Max Planck Institute (Leipzig, Germany), Dr. Timothy M. Ryan of Pennsylvania State University, Dr. Mulugeta Alene of Addis Ababa University (Ethiopia), Drs. Alan Deino and Gary Scott of the Berkeley Geochronology Center, Dr. Naomi E. Levin of Johns Hopkins University, and Dr. Beverly Z. Saylor of Case Western Reserve University. Graduate and undergraduate students from Ethiopia and the United States of America also participated in the field and laboratory activities of the project.
The project, which was funded by the Wellcome Trust, was led by Professor Mark Jobling from the University of Leicester’s Department of Genetics and the study is published in the prestigious journal Nature Communications.
The research team determined the DNA sequences of a large part of the Y chromosome, passed exclusively from fathers to sons, in 334 men from 17 European and Middle Eastern populations.
This research used new methods for analysing DNA variation that provides a less biased picture of diversity, and also a better estimate of the timing of population events.
This allowed the construction of a genealogical tree of European Y chromosomes that could be used to calculate the ages of branches. Three very young branches, whose shapes indicate recent expansions, account for the Y chromosomes of 64% of the men studied.
Professor Jobling said: “The population expansion falls within the Bronze Age, which involved changes in burial practices, the spread of horse-riding and developments in weaponry. Dominant males linked with these cultures could be responsible for the Y chromosome patterns we see today.”
In addition, past population sizes were estimated, and showed that a continuous swathe of populations from the Balkans to the British Isles underwent an explosion in male population size between 2000 and 4000 years ago.
This contrasts with previous results for the Y chromosome, and also with the picture presented by maternally-inherited mitochondrial DNA, which suggests much more ancient population growth.
Previous research has focused on the proportion of modern Europeans descending from Paleolithic – Old Stone Age – hunter-gatherer populations or more recent Neolithic farmers, reflecting a transition that began about 10,000 years ago.
Chiara Batini from the University of Leicester’s Department of Genetics, lead author of the study, added: “Given the cultural complexity of the Bronze Age, it’s difficult to link a particular event to the population growth that we infer. But Y-chromosome DNA sequences from skeletal remains are becoming available, and this will help us to understand what happened, and when.”
The study ‘Large-scale recent expansion of European patrilineages shown by population resequencing’ is published in Nature Communications.
It seems, however, that these social media applications do potentially more harm than good – by allowing archaeology and the future of collective cultural heritage to be swept away by naïve initiatives without strategic oversight. The archaeological record and the archaeological profession are at stake, local communities face unequal access to their own heritage and archaeologists themselves become all too often a subject of abuse and exploitation.
An article published today in Open Archaeology focuses on the current state of the social web in the development of archaeological practice, and reflects on various conscientious activities aimed both at challenging current online interactions, as well as at positioning archaeologists as more informed innovators of the web.
Sara Perry and Nicole Beale, both from The University of York, surveyed the field in search of active social web initiatives in archaeology, studying their development and evaluation and assessing their impacts on other people, on cultural heritage itself and on the world at large. They found out that archaeologists have been drawing on social media and crowdsourcing/crowdfunding tools since their appearance on the web, and also that despite this long history of involvement, there is little evidence that they are aware of their (often dangerous) impacts.
It seems that these social web applications have not only put archaeologists themselves in danger, exposing them to severe online harassment and abuse, but that they are also draw local communities into exploitative labour practices, and seemingly enable a devolution of responsibility for, and weakened oversight of, the archaeological record. In so doing, the use of the web appears to be relieving the government and the cultural custodians of their duties to protect and conserve the historic environment for the future.
The authors argue that archaeology could adopt a more obvious social justice stance, using web-based media to advocate for cultural change and to bring attention to the short-sighted politics which are threatening our collective cultural heritage.
- CBA History
- Support Us
- Group Publications