Since Humans and Neanderthals lived side-by-side IT IS POSSIBLE that humans
were the ones who buried the hominids. Following your line of thinking from
modern times to the ancient past I may add that, (hypothesizing here) since I
certainly see humans burying their beloved pets today in ritualistics ways, I
see no reason why ancient humans did not do the same with their domesticated
and beloved hominids. Tarzan would have done so with cheeta. Another "Just
so" story for the record.