Stone Age hunters in northern Europe made the sharp ends of their weapons from a surprising raw material: human bone. The choice may have had a symbolic purpose, such as imbuing the arrows with the skill of a dead expert hunter.
Before the arrival of farmers, Europe was inhabited by Stone Age hunter-gatherers. They roamed a landscape very different to today. The planet was deep in a glacial period, so lots of water was locked up in ice sheets at the poles – and sea levels …
Source: Humans - newscientist.com