An international team of scientists, including three UW-Madison researchers, has discovered fossilized remains of a previously undiscovered hominin species, totaling more than 1,500 well-preserved bones and teeth, according to a university release.
The fossils were found in a deep underground chamber of a subterranean labyrinth near Johannesburg, South Africa, where scientists believe they were deliberately placed.
UW-Madison paleoanthropologist and early human expert John Hawks co-directed the analysis of the fossils, which he said do not match any existing species.
The creature, named Homo naledi after the cave it was discovered in, was built for long-distance walking, Hawks said in the release. It had a small head and brain, hunched shoulders, a broad chest and thin limbs with a face that looks more like a human’s than an ape’s.
Getting to the fossils required a 20- to 25-minute commute, which included technical climbing of a feature called “Dragon’s Back,” inching through a 15-foot squeeze called “Superman’s Crawl,” and finally wriggling down a narrow, 12-foot-long chute in the dark, according to the release.
UW-Madison anthropology graduate student Alia Gurtov’s small stature and background in paleoanthropology made her an ideal addition to the team of six female scientists who made the treacherous descent to retrieve parts of at least 15 skeletons of all ages.
Hawks said the difficult climb down into the chamber, along with the position and completeness of the bodies, led his team to believe they were placed there on purpose.
“We think it is the first instance of deliberate and ritualized secreting of the dead," Hawks said in the release. "The only plausible scenario is they deliberately put bodies in this place."
Gurtov and the rest of her team, once finally in the cavern they named Dinaledi Chamber, spent six to eight hours underground each day painstakingly removing the fossils from the wet sediment at the bottom of the cave, sometimes with nothing more than a toothpick.
The project started last November when cavers found one skull but, soon after arriving, researchers found much more in the tiny chamber.
"It had the feeling of a tiny cathedral. It was just so still and dynamic at the same time. There was a sense of ages,” Gurtov said in the release. “It was absolutely silent. The floor was covered in skeletal material."
Just next door to Dinaledi Chamber is a classroom-sized vault where another team of about 30 paleoanthropologists piece together the collection of bones like a 1,500-piece puzzle.
UW-Madison Department of Gender and Women’s Studies postdoctoral fellow Caroline VanSickle works at the table dubbed Hip Heaven, comparing hip and pelvis bones to those of other hominins, according to the release.
Although her job is complicated, VanSickle said piecing together the creature’s hips could help answer many questions.
"At many other hominin sites where pelvis fossils are found, there will only be a few pieces from one or two individuals, but those pieces may be fairly complete," VanSickle said in the release. "The downside is that the Homo naledi fragments are far less complete than fossils from other sites, so figuring out how they fit together and what they mean for how Homo naledi walked or gave birth is much more difficult."
Among the questions that still need to be answered is the age of Homo naledi, which is difficult to date because of the cave’s unique geology, Hawks said in the release. The project will likely continue for years to also ascertain our new ancestors’ diet and where they might have lived.
