10 – Earliest evidence of stone tool use
3.4 to 3.3 million years ago
Stone tools may be the earliest inventions of our ancestors. A stone tool would have allowed hominins to access bone marrow and to process meat and other foods. This technology shows a cognitive leap in hominins, since not many animals can make and use tools. The earliest stone tools come from Lomekwi and date to 3.4 million years ago. There are also animal bones with cutmarks from butchering at a different site, Dikika, that are slightly younger, dated to 3.3 million years ago.
Image credit: MPK-WTAP West Turkana Archaeological Project (image found in Smithsonian Magazine online https://www.smithsonianmag.com/science-nature/oldest-known-stone-tools-unearthed-kenya-180955341/)
Environmental and Climate Changes
Continued aridity, enhanced seasonality—Loss of forests and savanna expansion 4.4 Ma