A new species of human relatives, Homo naledi, was recently discovered in a cave in South Africa.

There is much excitement surrounding the discovery in part because there is evidence that suggests this species may have buried their dead, a trait that has always been thought to be distinctly human.

According to PBS there is nothing but fossils in the cave where they were discovered and after eliminating alternative scenarios researchers suggest H. naledi journeyed through the caves purposely leaving bodies there over an extended period of time.

1,550 fossil pieces have been assembled into 15 skeletons and analyzed but questions still remain regarding the age of the fossils. Fossil dating can be very difficult especially if they are older than 50,000 years because carbon dating (the most common technique used for fossil dating) only works for more recent fossils.

NBC reported that due to the fact the fossils have not been dated and that we can’t say with certainty the species buried its dead, critics are calling the conclusions hasty and believe naming it a new species is premature.

The fossils of H. naledi suggest similarities to humans in their hands, feet and facial structures but also to primates with their curved fingers and small brains. Their place on our family tree however, is still up for debate.