What is the closet ancestor to a caveman?

Cavemen occupied the period known as the Neolithic Age, and are the earliest known examples of modern humankind. Modern humans are descended from the Cro-Magnon branch of Homo Sapiens- up until recently it was thought that they were the descendants of an earlier race called the Neanderthals, but modern archaeological and anthropological research has found that in fact, the two branches actually CO-EXISTED side by side (although the Neanderthals were probably the first to evolve). So Neanderthals were RELATED to us, but not our pre-Cro Magnon ancestors, who unfortunately are believed to have driven the Neanderthals to extinction by a series of huge ethnic cleansing activities. Both species of humankind can be classed as having been cave-dwellers, and in both cases, their closest ancestors were the primate apes- they both stemmed from the same evolutionary tree, but then branched off from each other.