BARCELONA. An international team has discovered in Ethiopia, a fossil of a hominid that existed alongside the Australopithecus afarensis Lucy, more than 3 million years ago, new link in the evolution of the human lineage.
The Spanish geologist Lluís Gibert , University of Barcelona (northeastern Spain) stressed the importance of finding, published today in the journal Nature , and wished to reopen the debate on human evolution.
“Whenever there is an important fossil, there is great scientific debate, and this new finding will generate further discussions on the human origins, “he said.
The dating and identification of the fossil, found in the 2011 season, is the final evidence that Australopithecus afarensis shared time and space with other species of hominids in the middle Pliocene in Africa.
Australopithecus deyiremeda is the name of the new species of hominid fossil discovered in the area of Woranso-Mille (Ethiopia) by an international scientific team led by Professor Yohannes Haile-Selassie (Reserve University Case Western, USA) and in which he has participated Gibert, researcher at the Department of Geochemistry, Petrology and Geological Survey of the Faculty of Geology.
The scientific team has found several fossils (lower jaw, upper and a collection of teeth) in deposits and Waytaleyta Burtele in Woranso-Mille, in the central region of Afar, about 50 kilometers north of Hadar and 520 kilometers northeast of the Ethiopian capital, Addis Ababa.
These fossil evidence, dated between 3.5 million and 3.3 years, have been assigned by the experts to a new species, Australopithecus deyiremeda .
As explained Gibert, the fossil was discovered during a raid in March 2011 on land that had been washed away by the rain and wind during the winter they did bring out new fossils in the Woranso- Mille.
“We only collect fossils are significant, especially primates and carnivores and everyone has to be on the stratigraphic context so poderles assigning ages. In recent years it has worked on the study of fossils, to refine the age of the fossiliferous layer that comes and understand the sedimentary environment, “said geologist.
” Perhaps most important of this finding is to realize for the first time two species of Australopithecus coexisted in time and space in the middle Pliocene, 3.5 million years ago, “said Gibert.
Up Now there was only one kind defined at the time, it was Australopithecus afarensis and therefore “all hominids (subgroup within hominids) were supposed to have evolved after that species.”
Other proposed hominids A.afarensis contemporaries came from Kenya ( Kenyantropus platyops ) or Chad ( Australopithecus bahrelghazali ), but according Gibert, “were received with some skepticism by the community paleoanthropologists, perhaps because there was no evidence on the ground of the coexistence of these species with A.afarensis . “
” But in Ethiopia itself that there is evidence that cohabitation, by So now it is important to review with an open mind the number of species of hominins in Africa during the middle Pliocene, a number that I think could range between two and four, “said the expert.
From this finding and “now we have a different scenario in African middle Pliocene with more than one species of hominin is important to know which of them evolved to give rise to the genus Homo,” Gibert said, so “it is necessary to recover more and more complete fossil in the middle Pliocene of Africa “.
” The question is whether the presence of several species of hominids in the middle Pliocene is also due to a change in the weather during this time that favored changes in the environment and training new species adapted to new environmental conditions. The sedimentary record can help us answer that question and are working on it, “the geologist.
According to experts, the species A. deyiremeda is clearly distinct from the A. afarensis in facial morphology characteristics , dental and jaw.
The thickness of the enamel also point to a pattern of diet richer and more varied than in the case of A. afarensis, and probably more similar to the genus Homo .
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