Stone Age 
A prehistoric period when weapons and tools were made of stone or of organic materials such as bone, wood, or horn.
The Stone Age covers a period of about 2.5 million years, from the first use of tools by the ancestors of humankind (Australopithecus) to the introduction of agriculture and the first towns. It is subdivided into the Palaeolithic, Mesolithic, and Neolithic periods, and is succeeded in Europe by the Bronze Age (or, sometimes, the Copper Age) about 5,000-4,000 years ago