Mohammad ALHADDAD
On February 1, 2016, an Ethiopian shepherd found an almost complete skull of one of the ancestors of humans, who lived 3,800,000 years ago.
The skull has moved from the shepherd's hand to the Ethiopian paleontologist Johannes Hella Selassie from the Cleveland Museum of Natural History at the University of Ohio, according to findings published in two studies published in the journal Nature on Thursday.
Lucy's ancestors
After three years of analysis by researchers at the Max Planck Institute for Human Evolution in Germany, they were able to date the fossil to 3.8 million years ago, identifying it as a bipedal Australopithecus anamnesis, a long-time human-like ancestor. Of the types of Australopithecus avarenes identified from the skeleton known as Lucy discovered in 1974.
The researchers hail the skull as one of the most important quasi-human discoveries of the last century. The new discovery challenges the ideas of how humans first evolved from ancestors of human-like monkeys.
The two studies also suggest that the process of development towards modern man has been through several paths and not one path as it was before.
They lived together
The skull remains contained separate parts of the jaw and teeth, enabling researchers to identify the shape of the face and the nature of the food that was eaten by early humans.
Australopithecus anamnesis was first identified in 1995 after four million-year-old teeth and jaws were found from Kenya.
Due to the time difference as well as many anatomical similarities, most researchers concluded that Australopithecus anamnesis gradually shifted and replaced with Australopithecus avarenesis, who lived between 3.7 million and 3 million years ago.
The results of the two studies suggest that the two species may have lived together in a single era for at least 100,000 years, before the most species of anamensis disappeared, while "avarinesis" developed.
Researchers are likely to return the skull to an adult male, despite its small size, has reached the brain size of about 370 cubic centimeters, or close to the size of the brain of chimpanzees.
The anatomy of the skull also helps to identify a 3.9 million-year-old puzzling forehead bone found in Ethiopia in 1981. "Anatomical comparisons indicate that the skull belongs to avarinesis. If that is true, Lucy's predecessor species," says Haile Selassie. Skull's new anamnesis, "concludes that the two species lived together about a hundred thousand years ago.
The research team still believes that Avarinesis is descended from the anamensis, but suggests that Lucy species branched out of the anamensis rather than merely replacing them.