Ethiopia is considered the site of anatomically modern humans emergence. Archeological discoveries in the country's sites garnered specific earliest fossils succession including the female hominin Australopithecus afarensis lived 3.2 million years ago, and Ardipithecus ramidus (4.4 million years ago). Human settlements in present-day Ethiopia began at least in Late Stone Age and agricultural revolution took place in the third millennium BC. Formulation of ethnolinguistic groups of Afroasiatic speakers (namely Semitic, Cushitic and Omotic) and Nilo-Saharan people shaped with new ethnic cultural and linguistic entity by the first millennium BC.