Researchers unearthed in Ethiopia dental fossils of about 2.65 million years of an unknown species so far in the human evolutionary lineage, which lived at the same time and in the same place as the first known member of the Homo genus, to which our species belongs.
The scientists discovered in the area of the Ledi-Geraru Research Project, in the Ethiopian northeastern region of Afar, 10 teeth -seis molar, two incisors, a premolar and a canine- that, as they concluded, belonged to a new species of Australopithecus. The teeth came from two individuals.
Until now, six species of the genus Australopithecus were known, an important ancestor of the first humans that presented a mixture of simiies and human features, from fossils found in various African deposits. According to researchers, newly found teeth have traits that indicate that they belong to a seventh species.
A genus is a group of closely related species that share similar characteristics. For example, lions and tigers are of the same gender but represent different species.
The scientists also discovered three other teeth of 2.59 million years ago that presented traits that indicated that they belonged to the oldest known homo species, one that was first revealed by a unexpected jaw in the same vicinity in 2013.
Scientists have not yet assigned names to the Australopithecus and Homo species represented by these 13 teeth due to the incomplete nature of the fossil remains. Our Homo Sapiens species is the most recent member of the Homo genre, since it first appeared about 300,000 years ago in Africa and subsequently extended throughout the world.
The new dental fossils provide information on a little known period of human evolution. The close antiquity of the teeth suggests that this kind of newly identified Australopithecus coexisted in this region with the first Homo species, which raises questions about whether they competed for the same resources.
The teeth also indicate that there were four hominins – as the species of human evolutionary lineage are known – that inhabited East Africa at that time.
Previous fossils showed that another species of Australopithecus and a kind of Paranthropus, a hominid with a specialized skull adapted for heavy chewing, lived in East Africa during this time.
Another species of Australopithecus also lived in southern Africa, so that the number of hominids in the continent amounted to five.
The presence of these contemporary hominids illustrates the complicated nature of the human evolutionary process.
“This reinforces the idea that the history of human evolution is not that of a single lineage that changes slowly over time,” says Paleoantropologist at the University of Nevada in Las Vegas Brian Villmoare, lead author of the research published Wednesday in the journal Nature.
“Rather, the pattern of human evolution is similar to that of other organisms, repeatedly brancing in multiple species throughout the fossil record, many of which lived at the same time,” Villmoare added.
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Ethiopian fossils reveal a new species in the human evolutionary lineage
Researchers are looking for clues about the nature of any interaction between Australopithecus and Homo species represented by the 13 teeth.
“We are currently analyzing the teeth to see if we can say if they ate the same,” said the Paleoecologist at Arizona State University and project co -director, Kaye Reed.
If so, they could have fought for resources, Reed said. According to the researcher, cough stone tools had been discovered in the vicinity of the same era, probably manufactured by the Homo species.
The researchers determined the age of the teeth through a technique that dated feldspar crystals contained in the volcanic ashes of the sediments where they were discovered based on the radioactive disintegration of the argon element.
The Afar region, one of the warmest and lowest places on Earth, is an arid extension of wastelands.
But at the time of these species, the rivers flowed through a landscape with vegetation towards shallow lakes in a landscape populated by a splendid variety of animals. Among them there were giraffes, horses, pigs, elephants, hippos and antelopes, as well as predators such as saber teeth and hyenas.
In general, it is believed that homo descended from a kind of Australopithecus, although the exact species and the moment of its appearance have been subject to debate. The Australopithecus ended up extinguishing.
Among the Australopithecus is the famous fossil Lucy, a member of the Australopithecus Afarensis species that lived approximately 3.18 million years ago.
Lucy’s remains were discovered in 1974, also in the Afar region.
According to the researchers, the newly discovered teeth presented characteristics that showed that they did not belong to the Lucy species.
“This new species of Australopithecus is not in any way a ‘lost link’, and in fact we do not believe that it was necessarily ancestral of any known species,” Villmoare said.
“Species arose and many became extinct,” Reed said. “Each finding is a piece of the puzzle that places human evolution in a branched tree, rather than in a linear graph.”
With Reuters information.
