Recent Findings Date Earliest Stone Tools at 3.3 Million Years Ago

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Recent findings in the Lake Turkana region of Kenya date the oldest stone tools back thousands of years earlier than what was originally thought. The oldest stone tools were previously thought to be made by human ancestor Homo habilis (Figure 1) 2.8 million years ago in modern-day Ethiopia. However, these new stone tools push that date back to 3.3 million years, and were not even made by a direct human ancestor (Figure 1).  

Figure 1: Differences in the parts of the skull (crania, maxillae, and mandibles) of Australopithecus africanus, Paranthropus boisei, and Homo habilis.

The tools were found alongside the teeth of Paranthropus boisei (Figure 1), a type of hominin, and co-existed with many human ancestors like the Homo habilis. The teeth being found with the tools could indicate that Paranthropus used these stone tools. Thirty of these stone tools were found at the Lomekwi 3 site of many fossilized animal remains, those remains showing signs of butchery. The animals at the site included ancient hippopotamus, antelope, and baboon. These stone tools included hammerstones, cores, and flakes, all tools used to skin or pound animals and animal meat. The use of stone tools opens up a lot of new food options in the competitive environment. Especially with the tough, leathery skin of a hippo, stone tools would be very beneficial to getting into the meat. Most likely, the Paranthropus found a hippo carcass and cut off the meat they needed, as there were not any stones used for weaponry at the site (Figure 2). 

Partially excavated bones and associated artefacts.
Figure 2: A fossilized hippo skeleton was found alongside the tools. Photograph by: T. W. Plummer

Different methods of dating were used to confirm the date of the tools, such as radioactive dating and geomagnetic reversal dating. Radioactive dating is a method of dating rocks and other minerals by tracking specific radioactive isotopes like uranium or argon. By determining the rate of decay of the isotope, a relative date of the tool in question can be gathered. Geomagnetic reversal dating works by tracking the number of complete reversals in the Earth’s magnetic field, specifically in the poles. These dating methods, together with site analysis, proved that these stone tools were around 3.3 million years old. However, experts question if Paranthropus even made the tools. Some scientists believe that there was no way for the Paranthropus to have used stone tools, as they have teeth that indicate a more vegetarian diet, negating the need for meat-cutting tools. Even if Paranthropus didn’t construct the tools, the earlier date of use is still quite significant. 

However, if Paranthropus boisei did make the tools, it shows a type of convergent adaptation, in that different lineages saw the need for the same type of object. It also goes against the idea that the modern human lineage was the only one capable of tool making for a specific purpose. Humans may not be the only ones capable of this sophisticated tool usage, other organisms can develop it as well, which is a notable development. 

References:

  1. BBC World News. “Ancient Stone Tools Found in Kenya Made by Early Humans.” BBC News, February 10, 2023. https://www.bbc.com/news/world-africa-64595418. 
  2. Hunt, Katie. “Sophisticated Stone Tools May Predate Humans, Study Suggests.” CNN, February 10, 2023. https://www.cnn.com/2023/02/09/world/first-stone-tools-hippo-scn/index.html.  
  3. Kreier, Freda. “Ancient Stone Tools Suggest Early Humans Dined on Hippo.” Nature News, February 9, 2023. https://www.nature.com/articles/d41586-023-00386-6.  
  4. Weule, Genelle. “Nearly 3 Million Years Ago, a Butcher Hacked up a Hippo with a Crafted Stone Tool. They May Not Have Been Human.” 2.9-million-year-old butchery site in Kenya suggests humans perhaps weren’t first to use crafted stone tools – ABC News, February 9, 2023. https://www.abc.net.au/news/science/2023-02-10/fossils-animal-bones-stone-tools-early-hominin-east-africa/101937222. 
  5. Smithsonian. “2.9-Million-Year-Old Butchery Site Reopens Case of Who Made First Stone Tools.” Phys.org, February 9, 2023. https://phys.org/news/2023-02-million-year-old-butchery-site-reopens-case.html.  

Further Reading

  1. Coleman, Jude. “New Caledonian Crows Keep Their Favorite Tools Safe.” Inside Science, February 15, 2022. https://www.insidescience.org/news/new-caledonian-crows-keep-their-favorite-tools-safe.  
  2. Muller, Antoine, Ceri Shipton, and Chris Clarkson. “Stone Toolmaking Difficulty and the Evolution of Hominin Technological Skills.” Nature News, April 7, 2022. https://www.nature.com/articles/s41598-022-09914-2.  

2 thoughts on “Recent Findings Date Earliest Stone Tools at 3.3 Million Years Ago”

  1. How do the wear pattern/condition of the Paranthropus teeth and tools echo each other? What do they tell us about the Paranthropus diet and the community’s relationship with nature back then?

    • The teeth of Paranthropus were generally stronger and built more for “crushing”, as compared to Homo habilis. Similarly, the wear pattern on the stone tools at the site mirrors the crushing function of Paranthropus’ teeth. The similar pattern shows that Paranthropus could have ate using tools or teeth interchangeably.

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