On September 10, 2015, a new hominin species was announced that changed our understanding of human evolution. Homo naledi was discovered in the Dinaledi chamber of the Rising Star cave system at the Cradle of Humankind in South Africa. I and approximately 40 other early career researchers studied the over 1500 fossils excavated from this site and concluded that no species like this had ever been discovered. Homo naledi were tall (5’4”) but lightweight, small-brained but but with human-looking feet. The core of their bodies resembled our early ancestors in the genus Australopithecus, while their extremities more closely resembled humans.
My part of this research was to analyze the pelvic remains from the Rising Star cave. Over 40 pelvic fragments were found, and they represented individuals of different ages. I found that the pelvis was a mixture of primitive and more modern features. The top was primitive: instead of the bowl shape seen in humans, Homo naledi has a more saucer-shaped pelvis that is similar to Lucy’s. The bottom was more modern: the sitbones (ischia) were short, a trait shared with all members of the human genus. Despite these more modern traits, the pelvis is much more primitive than expected for a species of Homo.
The Rising Star fossils were extremely difficult to excavate because they were deposited, perhaps purposefully, in a dark hard-to-reach chamber where no other animals would disturb them. How did a small-brained, somewhat primitive member of the human genus manage such a feat? We currently do not know, but are looking forward to the challenge of finding out. Homo naledi forces paleoanthropologists to reconsider a number of truths we thought were set in stone: depositing bodies may not be a uniquely human behavior; a humanlike pelvis and upper body are not a defining feature of our genus; and the evolution of humans is a more complex story than we could have ever predicted.
My research on Homo naledi:
- Two presentations at the American Association of Physical Anthropologists annual meeting in 2016:
Learn more about Homo naledi:
- Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa (eLife article on taxonomy)
- Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa (eLife paper on context)
- Mysterious New Human Species Emerges from Heap of Fossils (Scientific American summary)
- [Video] Homo naledi announcement
- Storify of the American Association of Physical Anthropologists session on Homo naledi in 2016
Media where I discuss Homo naledi and the Rising Star project:
- Remains of Humanlike Ancestors Found in South Africa: Discovery of bones of previously unknown species deep in a cave raises questions about origins of ritual burial, self-awareness (The Wall Street Journal)
- [Video] UW researcher talks about discovery of new species of human ancestor (News 3 This Morning, WISC-TV)
- New species of human found in South African cave: Wisconsin scientists help explore, identify Africa’s largest-ever find of fossilized bones and teeth (Milwaukee Journal Sentinel)
- Found with help from UW scientists, newly discovered species is ‘cousin’ of humanity (Madison.com)
- Hip Heaven (University of Wisconsin-Madison News, with video)