Acheulean Hand Axe (Homo Erectus) from Paleolithic age. This stone hand axe was a cutting tool used by early humans for a wide range of purposes, such as butchering animals and carving wood. The Acheulean (stone tool making) culture dates back to approximately between 1.65 million years ago and 100,000 years ago, in the Lower Paleolithic Age. Some types of rocks, such as flint, could be knapped into many tools, such as arrow and spear heads for hunting. Knapping is the process where a lump of rock is shaped into a tool by repeatedly chipping off small flakes.