Among the researchers taking part in this project is Bryn Mawr College Visiting Professor of Anthropology Caroline VanSickle.
The age of the original Homo naledi remains from the Dinaledi Chamber has been revealed to be startlingly young. Homo naledi, which was first announced in September 2015, was alive sometime between 335 and 236 thousand years ago. This means that these small-brained human relatives, or hominins, may have lived alongside early Homo sapiens. This is the first time that it has been demonstrated that another species of hominin survived alongside the first humans in Africa.
The research, published today in three papers in the open-access journal eLife, presents the long-awaited age of the Homo naledi fossils from the Dinaledi Chamber and announces the new discovery of a second chamber in the Rising Star cave system, named Lesedi, which contains additional Homo naledi fossils. These include a child and a partial skeleton of an adult male with a remarkably well-preserved skull.
VanSickle was a co-author of the 2015 manuscript announcing the discovery of Homo naledi and is a co-author of the new paper announcing the findings from the new cave chamber.
In 2014, she attended the Rising Star Workshop at the University of the Witwatersrand (Wits) in Johannesburg, South Africa. There, she and a large international team of researchers sorted through the 1000s of fossils that came out of the cave to figure out what they were, how they fit together, how many individuals were represented, and what species they were.
“My focus was on the pelvis, which generally in hominins (human relatives) tells us how a species walked, what their posture might've been like, and how they may have given birth,” VanSickle explains. “The Homo naledi pelvic remains are a collection of small fragments of incomplete bones, so many of these questions are still unanswered.
“In many ways, the pelvis of Homo naledi most closely resembles that of the 3 million year old hominin Lucy (Australopithecus afarensis), which is strange since the rest of the skeleton does not particularly resemble Lucy and now we know that Homo naledi lived much more recently than Lucy.”
When the excavation team found new fossil material in the Lesedi cave site within the Rising Star cave system in 2016, there was one fragment of the side of a hip. Researchers at Wits took a 3D scan of this fragment and sent it to VanSickle, who obtained a 3D print out of the fossil to study.
With the scan, print, and a few photos, VanSickle worked with researchers who were in South Africa to compare this new fragment to the ones they had from the original cave site (Dinaledi).
“The Lesedi fragment is interesting because it is the most complete immature hip fossil we have from this species so it can potentially tell us something about how this species grew,” says VanSickle.
While at Bryn Mawr, VanSickle continues to lead a team of researchers with expertise in torso reconstruction, hominin growth and development, and hominin pelvic to compare the pelvic remains from each cave site to each other and to other hominin species. The internationally dispersed team uses 3D scans of the fossils to collaborate remotely.
“In 2015, I thought the mosaic anatomy of this species was the most interesting part of the story: the small brain, Homo erectus-like head shape, australopith-like torso and pelvis, human-like foot, and gibbon-like shoulder are features that shouldn't belong in one body, and yet we had clear evidence that they all went together,” says VanSickle. “Now, in 2017, I find it incredible that this unusual skeleton belongs to a species that lived so recently that it overlaps with the earliest members of our own species.”
Learn more about this research from the University of the Witwatersand, Johannesburg. The team was led by Professor Lee Berger of the Evolutionary Studies Institute at Wits University in Johannesburg, South Africa, and a National Geographic Explorer in Residence.
This fall VanSickle will be teaching ANTH 101: Introduction to Anthropology: Prehistoric Archaeology and Biological Anthropology and ANTH 274: Bioarchaeology. In the spring (2018) she’ll be teaching ANTH 209: Human Evolution, ANTH 278: Paleoanthropology Methods, and ANTH 348: Women in the Paleolithic.
“You can bet my human evolution syllabus will be updated to reflect this news about Homo naledi.”