Rising Star cave is a site in South Africa where scientists have identified the fossil remains of a previously unknown hominin. Hominins are the group of living things that includes human beings and early humanlike ancestors.
The cave lies about 30 miles (48 kilometers) northwest of Johannesburg. The remains were discovered in 2013 by spelunkers (cave explorers). The spelunkers made their way through a series of narrow passages leading to a deep chamber. They discovered many fossilized bones in the chamber. The spelunkers then alerted local paleontologists (fossil scientists).
By 2015, an excavation team had recovered more than 1,500 fossilized bones from the site. They called the chamber Dinaledi, which means stars in the language of the local Lesotho people. Anthropologists recognized the fossils as belonging to a previously unknown hominin that they named Homo naledi. The anatomy of H. naledi shows a mixture of primitive and modern features. The hominin’s braincase is less than half the size of that of modern people. The anatomy of the hands and shoulder suggests that H. naledi were good at climbing trees. But the anatomy of the legs and feet show that H. naledi walked upright, much as do modern humans.
By 2017, more H. naledi fossils had been excavated from a second chamber discovered in the Rising Star cave system. The second chamber, called the Lesedi, has no direct connection to the Dinaledi chamber. The word Lesedi means light in the local language. The fossil remains of at least 3 individuals were recovered from this chamber. The remains include the well-preserved skeleton of a child and an adult male with a near complete skull.
Scientists have been unable to determine the precise age of the fossils. This fact makes it difficult to know how H. naledi was related to other hominins and to modern humans. Sediments associated with the Rising Star cave system suggest the fossil remains are between about 335,000 and 236,000 years old. The dates suggest that H. naledi lived at the same time as more advanced hominins in Africa.
Scientists are also puzzled by how the remains came to be in the cave. The cave contains almost no fossils of other animals. Many of the hominin fossils were discovered undamaged. The remains show no evidence of being bitten or chewed by predators. By studying the sediments in the chambers, scientists could see that the bones had not been washed into the site by floodwaters. The evidence may indicate the hominins somehow became trapped in the cave and died together. The scientists who examined the fossils suggested that H. naledi may have intentionally placed their dead at the site. But evidence of such behavior is unknown from the fossil record of other early hominins.
