It’s time to set another place at the table of human ancestry. A recent discovery in South Africa revealed a new humanoid ancestor, called Homo naledi. This newly discovered species was smaller than humans, with a brain size not much larger than that of a chimpanzee. However, the discovery came with a very special twist: Homo naledi buried their dead, something we had thought made humans unique among other animals.

The burial ground, for lack of a better term, was found in a cavern deep under a U.N. World Heritage site called the Cradle of Humankind. The site has provided a lot of evidence about early humans and related species, telling us much of what we know about that period in our development. The chamber itself was very difficult to get to, as some of the openings were a mere 18 inches high, so it required experienced cavers to find.

That find was amazing though. 1,500 bone fragments which, when pieced back together, revealed the bodies of 15 individuals raging from infants to the elderly. Paleoanthropologists, like most scholars who study the past, are used to working with only a few small pieces of a puzzle, and this was no different. Using the process of elimination, they determined that Homo naledi must have intentionally buried their dead because there weren’t any other options that made sense.

There were no other fossilized remains, which means that the bodies were not stored there to keep away predators or scavenger that might have been drawn by the smell of meat. Hiding food from scavengers is still a common practice, but there was no evidence of that. Further, they bones weren’t clawed or chewed, meaning they weren’t left there by predators either. And they couldn’t have been washed into the cavern. So the only option left is that living relatives put them there.