A rare skull of 3.8 million years throws new clues about how humans evolved

ADDIS ABABA: A skull of a “remarkably complete” primitive human of 3.8 million years old was discovered in Ethiopia, they announced on Wednesday a discovery that has the potential to alter our understanding of human evolution.

The skull, known as “MRD”, was discovered not far from the younger Lucy, the ancient ancestor of modern humans, and shows that the two species may have coexisted for approximately 100,000 years.

“This skull is one of the most complete hominin fossils over 3 million years old,” said Yohannes Haile-Selassie, the renowned Ethiopian paleoanthropologist at the Cleveland Museum of Natural History, co-author of two studies published Wednesday in Nature magazine.

“He seems ready to become another famous icon of human evolution,” joining the ranks of other high-profile hominid findings, wrote Fred Spoor of the Natural History Museum in London in a commentary accompanying the studies.

“Toumai” (of the species Sahelanthropus tchadensis) is about 7 million years old and some paleontologists consider it the first representative of the human lineage. It was discovered in Chad in 2001.

Ardi (for Ardipithecus ramidus, another species of hominid) was found in Ethiopia in 1994 and is believed to be around 4.5 million years old.

And Lucy, the famous Australopithecus afarensis, was discovered in Ethiopia in 1974 and is 3.2 million years old.

Australopithecus afarensis is one of the longest and most studied early human species.

The new skull, MRD, belongs to the Australopithecus anamensis species.

Discovered in February 2016 at the Woranso-Mille site, just 55 kilometers from where Lucy was found in the Afar region of northeastern Ethiopia, MRD offers “the first vision of Lucy’s ancestor’s face,” according to a statement announcing the finding.

Other lesser-known Australopithecus fossils date back at least 3.9 million years, but only had jaws and teeth. Without the skull, scientists’ understanding of the evolution of these extinct hominids has remained limited.

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A dream come true

The finding challenges a previously held belief about how humans evolved.

“We think that A. anamensis (MRD) was gradually becoming A. Afarensis (Lucy) over time,” said Stephanie Melillo of the Max Planck Institute for Evolutionary Anthropology in Germany, co-author of Nature’s studies.

But MRD reveals that the two species coexisted for approximately 100,000 years, the scientists said.

“This is a game-changer in our understanding of human evolution during the Pliocene,” said Haile-Selassie.

Melillo agreed, saying he also raised new questions as if the species competed for space or food.

Although small, it has been determined that the skull is that of an adult. Facial reconstructions show a hominid with projected cheekbones forward, a prominent jaw, a flat nose, and a narrow forehead.

To the researchers’ surprise, the skull represents a mixture of characteristics of Sahelanthropus such as “Toumai” and Ardipithecus as “Ardi”, as well as more recent species.

“Until now, there was a big gap between the oldest human ancestors, who are around 6 million years old, and species like” Lucy “, which are between two and three million years old,” Melillo said. But MRD “links the morphological space between these two groups,” he added.

At a press conference in Addis Ababa on Wednesday, Haile-Selassie described how Ali Berlino, a “local boy” from Afar, found the MRD jaw and immediately communicated it to Haile-Selassie.

The skull was soon found nearby, and workers spent days reviewing the land that was “one percent land and 99 percent goat poop,” Haile-Selassie said.

“People were not disgusted by that … but some of them, of course, had to cover their faces because the smell was very bad,” he said.

It was a small price to pay for the discovery of such a complete specimen, he said.

“I didn’t believe in my eyes when I saw the rest of the skull,” recalled Haile-Selassie, who described the discovery as “a eureka moment and a dream come true.”

Source: www.tribune.com.pk