Our 4-Million-Year-Old Ancestors Were More Like Us Than You Think

Scientists have virtually reconstructed the braincase of a four-million-year-old human relative, unraveling some of the mysteries held in the poorly-preserved fossil.

The researchers discovered the crusty cranium was made up of the spongy bone found in our own skulls. Other types of hominin skull examined, however, displayed striking differences. The scientists reported their findings in the Journal of Human Evolution.

6_27_Skull A person holds a human skull. Our own skulls, scientists think, had similarities with those of a four-million-year-old hominin. Getty Images

"This large portion of spongy bone, also found in our own cranium, may indicate that blood flow in the brain of Australopithecus may have been comparable to us, and/or that the braincase had an important role in the protection of the evolving brain," study author and University of the Witwatersrand scientist Amélie Beaudet said in a statement.

Read more: Ancient Rome: Limping Pompeii man was decapitated by stone in last-ditch eruption escape attempt

The ancient skull fragments belonged to a member of the Australopithecus group—an extinct hominin family which scientists think gave rise to our own genus: Homo. Modern humans are known as Homo sapiens.

The broken braincase was first dug up in the Jacovec Cavern in the Sterkfontein Caves near Johannesburg in South Africa. Although scientists have studied the specimen for decades, its fragmentary nature has limited their results. Advanced “virtual paleontology” imaging, the researchers said, allowed them to look inside the bones in fine detail.

6_27_Ancient skull Reserachers virtually reconstruct the ancient skull. Beaudet et al/Journal of Human Evolution

"Our study revealed that the cranium of the Jacovec specimen and of the Ausralopithecus specimens from Sterkfontein in general was thick and essentially composed of spongy bone," Beaudet said. "This large portion of spongy bone, also found in our own cranium, may indicate that blood flow in the brain of Australopithecus may have been comparable to us, and/or that the braincase had an important role in the protection of the evolving brain."

The team found the skull material was different to some other ancient hominin heads examined. The cranium of distant human relative Paranthropus—who lived less than two million years ago—was thinner and made of more compact bone. “This result is of particular interest, as it may suggest a different biology," Beaudet said.

The four-million-year-old bone fragments, she added, offer scientists “a unique opportunity to learn more about the biology and diversity of our ancestors and their relatives and, ultimately, about their evolution.”

This is the latest find to expand scientific understanding of our ancestors. Recent studies have shed light on the diets of our forebears. Scientists think ancient hunter-gatherers may have snacked on jerky, but Vikings, it seems, feasted on raw fish and tapeworms.

Editor's Pick