Scientists Discover Oldest Known Human Grave in Africa

Modern humans might share little in common with the Stone Age hunter gatherers who, 78,000 years ago, curled a dead child into the fetal position and buried it in a shallow grave in a Kenyan cave. But the humanity of their grief, and the care they demonstrated for the child, can still be felt by looking at those tiny human remains, arrayed as if still sleeping. Scientists don’t know whether the child’s family or community connected its burial with thoughts of the afterlife. In a way, though, their actions guaranteed the child would have another life. Unimaginably far into their future, the child is not forgotten and it offers a fascinating glimpse into how some past humans coped with death.

The 2-and-a-half to 3-year-old toddler now dubbed Mtoto (‘child’ in Swahili) was found in a specially dug grave now recognized as the oldest known human burial in Africa. The team that discovered and analyzed the child published their findings in this week’s issue of Nature. Extensive forensic and microscopic analysis of the remains and grave suggest that the child was buried soon after death, likely wrapped tightly in a shroud, laid in a fetal position and even provided with some type of pillow. The care humans took in burying this child suggests that they attached some deeper meaning to the event beyond the need to dispose of a lifeless body.

“When we start seeing behaviors where there is real interest in the dead, and they exceed the time and investment of resources needed for practical reasons, that’s when we start to see the symbolic mind,” says María Martinón-Torres, a co-author of the study and director of the National Research Centre on Human Evolution (CENIEH) in Burgos, Spain. “That’s what makes this so special. We’re looking [at] a behavior that we consider ourselves so typical of humans—and unique—which is establishing a relationship with the dead.”

Panga ya Saidi cave, in the tropical uplands along the Kenyan coast, is a key site for delving into the lives of ancient humans. In 2013, excavations there revealed the side edge of a small pit, and researchers used a tube to retrieve a sediment sample for dating. The sample immediately revealed the presence of some degraded and unidentified bones. It wasn’t until four years later that scientists began to suspect they’d found more than a few random remains. They dug about ten feet below the cave floor and found a circular, shallow pit tightly filled with an array of bones. But this surprise was shortly followed by another—the bones were in such a state of decomposition that any attempts to touch or move them turned them to dust.

So the team extracted the entire pit, protected it with a plaster encasement and moved it to the National Museums of Kenya in Nairobi, and later to a specialized laboratory at CENIEH.

In the lab, scientists unleashed a toolbox of techniques and technologies to peer inside and analyze the bones and soils of the sediment block. Carefully excavating a bit of the block revealed two teeth whose familiar shape provided the first clue that the remains might represent a hominin burial. As the scientists delved further into the block they encountered more surprises. They found much of the well-preserved skull and face of the child, including some unerupted teeth still found within the mandible. These remains helped to ascertain that the team was exploring the remains of a very young member of our own species—Homo sapiens.

The group employed microtomography, a high-resolution X-ray based technique to determine that more bones were inside the block. But the bones were fragile and powdery; their low density made them very difficult to distinguish in images from the surrounding sediments. To solve this challenge, those cross-section scans were paired with software that sharpened them and eventually reconstructed 3-D images of the bones in the block. The image of a child, seemingly at rest, began to emerge.

Mtoto’s bones were articulated in nearly the same positions they would have been in life, anatomically connected at some points, with only small settling movements corresponding to those commonly seen as a body decomposes and flesh and muscle disappear. While the right ribs, on which the child was lying, are flattened, the spine and even rib cage curvature remain amazingly intact. This and other aspects of the skeleton’s condition provide a compelling line of evidence that the child had been buried soon after death, rapidly covered by soil and left to decompose peacefully in the grave. It stood in stark contrast to various animal bones of the same age found nearby—they had been broken, battered and scattered as a result of being left in the open.

The pit’s mix of sediment also differed in color and texture from surrounding sediments, revealing that it was dug and later filled in. And the dirt yielded still more clues. Geochemcial analysis of the soil showed elevated levels of calcium oxide and manganese oxide, chemical signals consistent with those expected to be produced by the purification of a body.

The child was lying on its right side, with knees drawn to its chest. The right clavicle (part of the shoulder) and the first and second ribs were rotated about 90 degrees, a state consistent with the upper body being wrapped or shrouded. The child may have been prepared and tightly wrapped with a shroud of large leaves or animal skins—an act that would make little sense for a body regarded as simply a lifeless corpse.

Finally, the position of the head suggests a tender touch. The first three cervical vertebrae, still attached to the base of the skull, were collapsed and rotated to a degree that suggests that the child was laid to rest with a pillow of biodegradable material under its head. When this pillow later decomposed, it appears that the head and vertebrae tilted accordingly.

Durham University archaeologist Paul Pettitt, an expert in Paleolithic funerary practices not involved with the research, called the study an exemplary exercise in modern forensic excavation and analysis. The totality of evidence seems to show that some person or persons cared for the child even after death. But what thoughts the ancient humans had about the dead is an intriguing question that may never be answered.

“The point at which behaviors towards the dead becomes symbolic is when those actions convey a meaning to a wider audience, that would be recognized by other members of the community and may reflect a shared set of beliefs,” says Louise Humphrey, an archaeologist at the Centre for Human Evolution Research at the Natural History Museum, London. “It’s not clear whether that’s the case here, of course, because we don’t know who attended the burial, whether it was the action of a single grief-stricken parent or an event for the larger community,” adds Humphrey, who wasn’t involved in the research.

Mtoto’s community was becoming increasingly more sophisticated. Surrounding soils in the cave from the same age as the grave are replete with an array of stone tools. The array of implements found suggests that Homo sapiens may have performed this burial during an era when they were gradually developing and using more advanced tool technologies.

Interestingly, the child wasn’t buried in some out of the way locale. It was buried at home. Panga ya Saidi cave is a key site inhabited by humans for some 78,000 years, until as recently as 500 years ago, and it also houses other, much younger burials. It remains a place of reverence for local humans to the present day, archaeologist Emmanuel K Ndiema of the National Museums in Kenya told reporters in a press conference unveiling the find.

The body was also found in a part of the cave that was frequently occupied by living humans. Martinón-Torres says this suggests a kind of relation between the dead and living, rather than the practical act of simply disposing of a corpse.

Mtoto The Sleeping Child

Watch on

The bones were securely dated to 78,000 years ago. Though the date places Mtoto as the oldest human burial known in Africa, the child is not the oldest burial in the archaeological record. Burials of Homo sapiens at Qafzeh Cave, Israel, some 100,000 years ago, included pieces of red ocher, which was used to stain tools and may have been employed in some type of burial ritual. Iraq’s famed Shanidar Cave, which saw burials by Neanderthals, suggests another way in which Homo sapiens and Neanderthals may have been more similar than scientists once believed.

But evidence for funerary practices among Paleolithic humans and Neanderthals alike remains thin on the ground. That’s especially true in Africa, where it may be that scientists simply haven’t looked enough, as much of the continent has yet to be investigated. Climate works against African preservation as well, and different humans in different regions may have practiced different types of mortuary rituals as indeed they still do today.

Pettitt notes that the majority of humans who lived in Pleistocene—from 2.5 million to 11,700 years ago—Africa or Eurasia are archaeologically invisible. “They could have been tucked away in vegetation, floated off down rivers, placed on hills and high places...or simply left behind when the group moved on,” he notes.

If burial wasn’t standard Pleistocene practice, it begs the question why humans sometimes went to greater lengths to inter contemporaries like Mtoto. Pettitt leans towards the idea that such deaths were outside the norm.

The death of a child may have tended to spur humans to undergo the rigors and ritual of burial. A high ratio of child graves exist among the few Pleistocene sites that survive, including both of the earliest African burials, Panga ya Saidi and South Africa’s Border Cave, and many sites of Europe and Asia. Pettitt adds that among some hunter-gatherer societies the death of infants or children is viewed as unnatural and disturbingly out of the norm. “I wonder if these reflect the distinct treatment of dead infants that reflects societies emerging horror at such abnormalities?”

If Mtoto’s death caused exceptional grief, the child’s careful burial and the grave’s unlikely survival to the present day somehow create an equally exceptional connection between modern and ancient humans. In the physical world, ancient humans had to confront death too, and might such burials suggest that they also had symbolic thought about those that died?

“Somehow these types of funerary rites and burials are a way humans have to still connect with the dead,” says María Martinón-Torres. “Although they have died, they are still someone for the living.”

Brian Handwerk | READ MORE

Brian Handwerk is a science correspondent based in Amherst, New Hampshire.