The Stone Age lasted 3.4 million years and 99 percent of us
Stone tools with edges, points, or striking faces define a span from roughly 3.4 million years ago until metalworking between 4000 and 2000 BC. In Western Asia bronze's spread by about 3000 BC closes the age—though gold and copper ornaments already glittered earlier.
Because of that enormous timescale, the Stone Age covers about 99 percent of human technological prehistory. It is the first rung of the three-age system used especially in Europe and western Asia, followed by Bronze and Iron Ages, and is itself split into Paleolithic, Mesolithic, and Neolithic. American archaeology uses different Lithic-stage markers with regionally shifting dates. Artefacts include tools of modern humans, earlier Homo, and possibly Australopithecus and Paranthropus; bone tools exist but preserve poorly.
The period tracks genus Homo's evolution, centered on the East African Rift, except that earliest tools may predate Homo. From about four million years ago a transcontinental savannahstan biome stretched from South Africa through the rift and Asia to China, the grassland stage for Homo erectus. Oldest indirect evidence is 3.4-million-year-old animal bones with cut marks from Ethiopia's Lower Awash Valley. Lomekwi 3 in Kenya yields 3.3-million-year-old tools; earlier Gona, Ethiopia, finds once held the record. Which species knapped Pliocene stone remains unknown—garhi, aethiopicus, or early Homo fragments lie near Gona-aged sites.
In July 2018, researchers reported possible oldest tools outside Africa in China at about 2.12 million years, if confirmed. Melting and smelting copper—not mere cold ornament—marks the Stone Age's end. The age is less a lifestyle brand than deep time's default: almost everything humans ever made with a sharp rock.
Source: Stone Age
