Without metal to make a weapon from, minifigs in prehistoric times had to use the strongest material they could find: bones. Did they use the bones of animals or of their deceased love ones? Well I guess that was a matter of preference. 

To make a weapon, they serrated the bones and tied them to a wooden stick, creating this beautiful Bone Spear. What armor goes great with bone weapons? The carcass of a dead animal! And you can create your own prehistoric minifig with the Sabertooth Helm and Sabertooth Armor.