Deep under South Africa’s Rising Star cave system, scientists discovered the fractured skull of a Homo Naledi child called “Leti” in a dark tunnel just 6 inches (15 cm) wide. It’s unknown how the little skull ended up in such a remote part of the cave, but the finders think it might be evidence of intentional burial.
“Leti,” short for “Letimela” or “Lost One” in the Setswana language of South Africa, lived between 335,000 and 241,000 years ago, according to the dates of other bones recovered in the enigmatic cave. Since the discovery of the first Homo Naledi fossils in the Dinaledi Chamber in 2013, about 24 Homo Naledi individuals’ fossil parts have been found throughout the cave system.
The cave’s existence of so many individuals of a single species is perplexing. The sole way in is by “The Chute,” a 39-foot (12-meter) vertical fissure that geologists and spelunkers have identified to be the only way into the tunnels. Leti’s little skull was found in parts about 2.6 feet (80 cm) above the cave floor, on a limestone ledge. According to Maropeng Ramalepa, a member of the exploring team, the place is surrounded by “a spiderweb of constricted passages.”
A Difficult Forefather.
The location is hardly navigable for skilled spelunkers using modern equipment, according to new study published Thursday (Nov. 4) in the journal PaleoAnthropology. There are no gnaw marks or traces of predation on the H. Naledi bones, indicating that they were transported into the cave by animals. The bones seem to have been put in the cave rather than washed in since they were not discovered jumbled with dirt or other trash.
That offers the possibility that our predecessors with orange-sized brains voluntarily entered a dark, maze-like cave, maybe down a vertical chute that narrows to 7 inches (18 cm) in portions, and buried their dead there more than 240,000 years ago.
Anthropologist Lee Berger (right) presents Leti’s skull outside the Rising Star cave system. The photographer is from Wits University.
Aside from the Rising Star cave system fossils, no tools or artifacts were found. Other than two juvenile baboons, at least one of whom may be much older than the Homo Naledi bones, there are little signs of other animals visiting the caves.
This human progenitor lived at the same time as early Homo sapiens, according to John Hawks, an anthropologist at the University of Wisconsin-Madison who analyzes the bones. According to Hawks, their apparent journeys within the cave show that they were among modern humans’ smarter forefathers and that they had mastered the use of fire to light their explorations. According to the Smithsonian National Museum of Natural History, H. Naledi walked upright, stood roughly 4 feet, 9 inches (1.44 m) tall, and weighed between 88 and 123 pounds (about 40 and 56 kilograms).
The tiny skull, which is small enough to fit in the palm of a contemporary human hand, should reveal more about H. Naledi’s development and evolution. While researchers have found a few jaw pieces in the cave from children, this is the first time they’ve discovered bones from the skull case or cranium. There were additional six teeth identified.
Bones and teeth
While excavating the tiny, winding tunnels encircling Dinaledi Chamber, the bones and teeth were uncovered. Researchers searched 1,037 feet (316 meters) of these passageways for signs of another entrance into that chamber or another nearby where remains have been uncovered. They couldn’t find any evidence of an alternative route.
Leti has a total of six incisors. The photographer is from Wits University.
In a paper published in PaleoAnthropology, archaeologist Marina Elliott of Simon Fraser University in British Columbia, Canada, wrote, “Exploration of the narrow passages within the Dinaledi Subsystem requires considerable effort, navigating areas with irregular floors and walls, numerous obstructions, and fissures less than 30 cm [11.8 inches] wide.”
However, in this deep maze, the researchers unearthed more fossils. A single-arm bone that most likely belonged to H. Naledi; a trove of 33 bone fragments that also most likely belonged to an H. Naledi person or individuals; and Leti, the cave’s second-ever piece of evidence of a juvenile baboon. On November 4th, details about Leti’s skull were published in the journal PaleoAnthropology.
The skull was split into 28 parts after it was partly preserved. The reconstruction of these pieces showed the majority of the child’s forehead and part of the top of the skull. Among the teeth, there were four unworn permanent teeth and two worn baby teeth. The child was about the age when the first permanent molars burst through the gum line, based on their development and wear. In a human child, this corresponds to roughly 4 to 6 years of age. H. Naledi may have developed faster than Leti, and if so, Leti may have perished while he or she was less than four years old.
A facsimile of Leti’s skull is held by Lee Berger. The photographer is from Wits University.
Based on the size of her skull, which is roughly 90% to 95% of the brain volume of adults of her species, Leti’s brain has a capacity of between 29 and 37 cubic inches (480 and 610 cubic cm).
In a press release, Juliet Brophy, an anthropologist at Louisiana State University who performed the research on Leti’s skull, remarked, “This starts to bring us insight into all phases of life of this fascinating animal.”
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