Story by John Hawks for American Scientist
The Rising Star cave system, part of the Cradle of Humankind World Heritage Site in South Africa, has been well mapped and was explored by cavers for many years, but without any fossils being noted there. That changed in September 2013, when two South African cavers, Rick Hunter and Steve Tucker, entered a remote, unmapped chamber and found the first-known fossil bones of what is now called Homo naledi strewn across its floor. Hunter and Tucker were working with South African paleoanthropologist Lee Berger, hoping to identify new cave settings with evidence of our fossil ancestors and relatives. Berger quickly organized an excavation to explore the contents of the extremely difficult-to-access site, named Dinaledi Chamber.
Since the discovery, I have been privileged to be a member of the scientific team investigating the find. The remote chamber would prove to contain a bone bed of an extinct population, more than 1,500 fossil specimens of which have been located so far—one of the most significant finds in the history of studying human evolution. That remarkable discovery has rippled excitement throughout the anthropological community, not least because the species’ traits do not make clear where it fits into the human evolutionary tree.