July 1, 2011
I spent almost the entire day in Nairobi. During this trip to the city, I met with Dr. I. O. Farah, who is the Director of the National Museums of Kenya. Our projects depend on collaboration with the NMK. The Kenya Museums have been a wonderful partner in supporting our excavation projects over the years. And the Smithsonian has helped trained the Kenyan staff of the NMK for over 25 years in everything from collections management to building exhibits, and we’ve also supported Masters and PhD training of some of the NMK’s scientists.
After an enjoyable discussion with Dr. Farah, I had two other interesting meetings. The first was with Dr. Christian Tryon of New York University, who also used to work with us in the Human Origins Program at the Smithsonian. Christian is an expert in stone technology during the transition from handaxe technology to the smaller, more diverse technology of the Middle Stone. In other parts of Africa this transition seems to occur sometime between 285,000 and 125,000 years ago. At Olorgesailie, handaxes drop out of the picture after 490,000 years, and don’t appear in any layer younger than 340,000 years old.
So here’s the question we are testing in our excavations: Could it be that stone tools in the layers at Olorgesailie tell us about the oldest known transition from handaxes to the Middle Stone Age? We’ll need a lot of digging and evidence to know this for sure.
There’s even an older part of the story. Last year, our team excavated a site dated 625,000 years old. There we found nearly one thousand stone tools. Christian, Alison, and I spoke about these tools because they indicate that even during the handaxe period, early humans were beginning to hit upon a new way of knapping stone. This new approach to toolmaking involved making smaller flakes by carefully planning how you strike one stone against another. Through careful preparing of the stone core ahead of time, flakes of a pre-determined size and shape could be struck from it using a hammerstone or a piece of wood. In other words, this new approach to flaking stone required good and careful planning. It’s a pretty brainy thing to do!
As I was talking with Christian, another good friend, Dr. Tyler Faith, walked into the lab where we were. Tyler recently graduated with his PhD from George Washington University in DC, close to the Smithsonian. He and I have been planning for some time to look at fossils my team had excavated many years ago at a site called Lainyamok, near to Olorgesailie in Kenya. I originally thought that a nearly complete skull of an antelope we dug up was most similar to a species known as the blesbok, which lives today in southern Africa. Tyler restudied the skull, comparing it to new fossil teeth he’s recovered from another Kenyan site.
Today, after our discussion and study of the fossils with fresh eyes, Tyler and I agreed that the skull I discovered more than 25 years ago and the fossil teeth he’s recently found belong to a new fossil species – distinct from the blesbok but closely related to it. Differences in the position and shape of the horns, the angle of the braincase at the back of the skull, and the look of the teeth are all significant enough to distinguish the fossils from any living species of antelope. Pretty cool stuff! We’ll write up the report of our findings over the next few months.
After saying our goodbyes to Christian and Tyler, who are headed out to a field site in western Kenya, Alison and I jumped into our car and braved the huge traffic jam coming out of Nairobi. It seemed like a battle, and we arrived in camp just in time for dinner.