The Oldowan, sometimes spelled Olduwan, is the archaeological term used to refer to the earliest stone tool archaeological industry in prehistory. Oldowan tools were used during the Lower Paleolithic period, 2.6 million years ago up until 1.7 million years ago, by ancient hominins across much of Africa, South Asia, the Middle East and Europe. This technological industry was followed by the more sophisticated Acheulean industry.