Oldest stone tools known to date found in Kenya

The oldest stone tools by far have been found on the western shore of Lake Turkana in Kenya. However, who made them or why are still not discovered.

The Kenyan tools, which have been existed for 3.3 million years, are much older than the current earliest known Homo fossils (2.8 million years old) and they are remarkably big.

On average, the cores stretch about 6 inches (15 cm) long and wide and weigh some 7 pounds (3.2 kg), according to the report made by Sonia Harmand and Jason Lewis of Stony Brook University in New York.

Scientists remain confused about the usage of the Kenyan tools. Harmand believed the purpose was to make sharp-edged flakes for cutting, but exactly how the tools were used is not known.

As to the question that who made the tools, candidates include some Homo species, the skeleton nicknamed Lucy and a creature called Kenyanthropus platyops, known from remains found not far from the site of the stone tools.

It was long assumed that tools were only made by our genus, "Homo" members, but the new finding proves that tool-making may have begun with smaller-brained forerunners and the Kenyan tools may constitute a pre-Homo tool culture.