A cave containing fossils of the ancient human relative homo naledi may be the world's first known non-modern human burial site with only female remains. The discovery of multiple female fossils in the cave, with some reports suggesting as many as 20, has led scientists to this conclusion, although the reason for the apparent absence of male fossils is unclear. Protein analysis of the fossils has reportedly found no male markers, supporting the theory that the site may be an all-female burial ground.