Sonia Harmand examining one of the oldest known stone tools discovered in Kenya. Photo: Stony Brook University/PA Wire

Stone tools were being used 3.3 million years ago by creatures that predated the earliest known ancestors of modern humans, scientists have learned.

The discovery, in Kenya, pushes back the origins of the archaeological record by almost a million years.

Until now it was thought that stone tool culture began around 2.6 million years ago with the appearance of Homo habilis, or ‘handy man’, the earliest known member of the human genus family that includes people living today.

The new tool artefacts, unearthed from the Lomekwi 3 (Lom3) archaeological site next to Lake Turkana in Kenya predates the ‘Oldowan’ H. habilis tools by around 700,000 years.

Scientists found a collection of anvils, hammer stones, worked cobbles and cores for making sharp edges used for cutting.

The discovery pushes back the origins of the archaeological record by almost a million years

The makers of the Lomekwi tools had a strong grip and good coordination, but may not have been quite human. Markings on the stones indicate they were used vigorously to pound items or produce sharp flakes.

But the arm and hand motions involved were probably more like those chimpanzees use to crack nuts than clearly recognisable human actions.

Writing in the journal Nature, the team led by Sonia Harmand, from Stony Brook University, the US, said: “The technological features of flakes and flake fragments are clear, unequivocal and seen repeatedly, demonstrating that they were intentionally knapped from the cores.

“The use of individual objects for several distinctive tasks reflects a degree of technological diversity both much older than previously acknowledged.

“The arm and hand motions entailed in the two main modes of knapping suggested for the LOM3... are arguably more similar to those involved in the hammer-on-anvil technique chimpanzees and other primates use when engaged in nut cracking than to the direct freehand percussion evident in Oldowan assemblages.”

The only hominin, or human-like creature, known to have been living in the area at the time was Kenyanthropus platyops (flat-faced man from Kenya) but there is no proof that it made the tools.

Sharp-edged stone tools had previously been directly linked to the emergence of the genus Homo in response to climate change and the spread of savannah grasslands.

Modern humans, Homo sapiens, are now the only members of the genus left on the planet.