Nine years ago, a new species of hominin was discovered in South Africa and was named Australopithecus sediba. According to research published in 2012, sediba, which means “source” in the South African Sesotho language, fed on leaves, fruits, nuts, bark of trees and other plants .
However, a new study developed by a group of international experts, led by the University of the Witwatersrand in Johannesburg (South Africa) and published in Nature , refutes this idea after observing that their teeth and jaws could not be adapted to this diet . The new research better describes the characteristics of this new species of hominin, which lived less than two million years ago in wooded terrain and which could be a link between the South African man-ape ( Australopithecus africanus ) and the first men.
According to anthropologist David Strait of the University of Washington in St. Louis, “Most australopithecines had incredibly efficient adaptations to their jaws, teeth, and faces that enabled them to process foods that were hard to chew or break . They were certainly capable of effective biting. applying great force, “he explains.
But Australopithecus sediba seems to be an exception among its Australopithecus cousins, since its maxillary structure prevented it from applying great pressure when chewing . “If he had tried to bite with all his might with his molars, applying the maximum power of the chewing muscles, he would have dislocated his jaw,” says Justin Ledogar of the University of New England. The study reached these conclusions after carrying out biomechanical tests on the skull of an Australopithecus sediba in a computer program.
The researchers analyzed the remains of the two skeletons – a child and a woman – found in 2008 in a cave in the South African region of Sterkfontein , 40 kilometers from Johannesburg, an area declared the cradle of humanity due to the large number of fossils it houses . These tests are similar to the biomechanical tests that are done today to measure the resistance to rupture of airplanes, cars and many other machines. Although the work does not raise the possibility that sediba is a close link to the first humans, it does provide evidence about the influence that dietary changes among hominids had on the origin and evolution of our species .
And it is that humans also have limitations in the force with which we can bite or crush food , perhaps similar to those of the most primitive, while other australopithecines did not have so many limitations, which implies that some populations of australopithecines evolved to strengthen their maxillary structures, while others, such as sediba, evolved in the opposite direction.
Imagen. Crédito: WUSTL GRAPHIC: Image of MH1 by Brett Eloff provided courtesy of Lee Berger and the University of the Witwatersrand.
