Sonia Harmand & Hélène Roche

Human origins written in stone. The Early Stone Age of West Turkana, Kenya

Hélène Roche and Sonia Harmand will present, past and new evidence on the Early Stone Age of the Turkana basin since Richard Leakey noticed the first stone tools on the west side of the lake while excavating the Turkana Boy in 1984. They will discuss the evidence in light of biological and environmental changes in East Africa and will present future research directions.

FULL TRANSCRIPT 

Good morning everyone. It is an honor for me to open the third day of this conference hoping your concentration is still at its highest. Thank you, Lawrence. Where is Lawrence? Thank you Lawrence. Thank you Fred for organizing this conference. Richard, it's a very special one for all of us, for me. Thank you Alicia also for making it happen. So it is indeed, sorry. Great to see you all today, to have the chance to spend time together. Richard would've been very pleased. The past three days we've been talking about science, about new discoveries, new projects, maybe new collaborations. We have also been enjoying good food, good wine at good restaurants, and I also know Richard would've definitely approve of that. Today my talk is titled Human Origins Written in Stone, the Archeology of West Turkana Kenya. I'm not going to make any announcement. I have a couple of things from the field, but I can unfortunately not talk about that today. It's too early, so I'm going to give a review of the archeology in West Turkana, in Turkana, general, nothing too boring I hope for all of you. There are not many archeologists in the room. I'm glad by the way, that obviously Berger became an archeologist, so that's fantastic. Very happy about that. 

Helen Roche couldn't be with us today. She sent photos and a little text that she asked me to read on her behalf. I will do so in a few moments after a brief introduction. So, we are here to celebrate Richard as a person as a scientist. Richard had a tremendous impact on the understanding of human origins and he's probably more known as a paleoanthropologist, at least in our field.

When we think about Richard, we think first about his important discoveries of hominin fossils, and the last few days it has been delightful for me to see all these pictures of Richard, Meave, Kamoya and others in the field looking for hominins excavating them carefully, piecing them together. I had never seen most of these pictures before, so thank you very much. I am, by the way, struck by the pictures of the different base camps. It is like nothing has changed. We're still using the same chairs, the same tables, the same tent, the sunscreens, et cetera. But so maybe something that is less known, although it has been mentioned by some of the speakers, is that Richard cared also about stone tools, and he knew about them. When I first met him at the end of the 1990s when I was a graduate student at the NMK and when I also met Louis, I was immediately impressed by the depth of his interest in stone tools and his interest in human prehistory at large was truly inspirational for me. 

I always felt deeply supported by Richard as a mentor, a friend, sometimes a father, and it never faded away. His support was also probably part of his strong advocacy for women in paleoanthropology and for him this was a family tradition. As the son of legendary archeologists, Mary and Louis Leakey, young Richard had been early on, well-trained on stone tools, particularly with Mary. The love story between the Leakey’s and African archeology started almost 19 years ago. I said 19? 90 years ago. When Louis Leakey in 1934 used the word Oldowan for the first time in his book, Adam's Ancestors, the Evolution of Man and His Culture. From the late 1930s, Mary and Louis had been finding prehistoric stone tools in Olduvai where Richard joined the work early on archeological digs with his mother, and we should not forget the Dalmatians. It is Mary who first defined the Oldowan in 1966 in her nature paper from sites dated at 1.8 million in bed one at Olduvai Gorge. She was also the first to create a system to classify Oldowan artifacts based on their assumed use. Later in the 1960s, Maryanne Louis found Homan fossils in association with those Oldowan tools that look more like later humans than Australopithecines discovered there previously. They decided to assign the Oldowan to a new species Homo habilis. 

This presumption that earliest Homo made the earliest stone tools is going to remain strong until quite recently. The Leakey work brought unparallel enthusiasm and attention to the prehistory of East Africa and following their success, a number of international projects began systematic archeological field work during the 1960s and 1970s, primarily in Kenya and Ethiopia. From there and based on the results of several generations of field research, more and more Oldowan sites were discovered. Some of them have pushed back the origins of hominin technology to much more ancient time. Sorry for this slide, probably not super elaborate, but just to tell you that we have now several dozens of complexes of sites in Africa dated between 2.6 and 1 million. A dozen localities for sites older than 2 million, but after 2.6, 2.5 million, the record is very light. We have only three sites with stone tools and since 2011 we have one outlier not Oldowan but this one I would come back to it later.

Stone tools were rightly described by Louis Leakey as fossilized human behavior. Stone tools are indeed snapshots of past hominin behaviors. They are the most staggering evidence for these behaviors. They give insight into past cognition and skills, their viability and their evolution through time. In the Turkana Basin sites with stone tools are many. We've for some of these most important site first ones discovered by Richard and Kamoya. Since then, decades of research had shown that the Turkana Basin is a source of unmatched archeological evidence for the continuity of hominin occupation and the richness of its Plio-Pleistocene sites and beyond. Turkana is also the cradle of innovation; I like to call it that way. In the past 10 years, it has produced some of the most striking evidence of human behaviors to name some, and of course I couldn't put all of them on the slide. The oldest archeological site in the world, the oldest Acheulean site in the world, the earliest and largest monumental cemetery in Eastern Africa built 5,000 years ago. The earliest evidence of warfare 10,000 years ago, shown by Marta and Rob who are here in the audience today and today also my colleague archeologist Emmanuel Ndiema, will give a talk on pastoralist resilience in Turkana. 

But for now, it is time for me to give the floor to Helene difficult she's not here and this is when my talk is going to be a bit special. I'm going to play her slides and I'm going to read the text that she sent me yesterday. It will be a bit of a special exercise for me because the text is written at the first person. So I'm going to be Helen Roche for some minutes, which I always try not to be, but let's do it. After this, I will present three main discoveries made by the West Turkana Archeological Project, nothing too detailed, nothing to bore you about. And I would like to say right now that of course what I'm going to present is the result of the collaborative work of fantastic colleagues. Some of them are here in the room like Craig, and Jason, Louise, the co-director of the project. So, this is now when I'm going to Helene Roche. So again, this is Helene and Helen, hello, by the way, I know she's looking at me, so I have a lot of pressure. Good morning everyone. I am very sorry not to be with you in real, but Sonia will be my voice. Such is life or I should say such is the French administration. 

No details. Since our friendship has been a very long story, I would like to share with you a few personal notes about Richard. 

The first time I met him was in Hadar, oops, sorry, I need to go back in Ethiopia, where as an archeologist, I was a member of the international team working there. In October 1974 after the discovery of several mandibles and just before the discovery of Lucy, Don Johanson and Maurice Taieb sent Richard a message inviting him to visit us in the field. He had flown from Nairobi with Meave, Mary, and John Harris. I was very impressed of course, and I remember the only words I was almost able to pronounce were to shyly ask Mary if she authorized me to study some Olduvai material for my PhD, to which she said yes, of course, a few weeks later I was in Nairobiwait to do so. Richard's office was still in the small volcanic stone buildings, and you had to climb a small external stair, sorry, not chair stair to reach him. After the customary greetings and still very shyly I asked him, I would like to see Mrs. Leakey, which one he answered. There are so many laughing at my disconcerted face. At that time I was not yet used to his incredible and almost permanent sense of humor. 

After having finished my PhD and since we were not able to go back to Ethiopia, I was desperately looking for a field work in East Africa. I had returned to several people, including Richard, but he has been the only one to respond positively. Just saying, come and we will find something for you. So, in February 1983, I flew again to Nairobi, and I was offered the Acheulean site of Isenya. I have to confess that I was a bit disappointed because what I was dreaming about actually was to work in the earlier Plio-Pleistocene. But Isenya was an interesting and challenging site anyway, which I started to excavate in August the same year. I was quite busy with my hundreds of handaxes and cleavers when in 1985, Glynn Isaac suddenly passed away. This was a big blow for all of us and moreover for Richard, because they've been working together since the beginnings in the 60s at Peninj. The year after Richard took me for a short trip to West Turkana where at that time, he was excavating the Turkana boy with Kamoya Kimeu. Having surveyed the Nachukui formations outcrops from south to north in search of fossils, their team had found lithic evidence suggesting the existence of archeological sites, some possibly dating to very early periods. 

In a few days, I was shown about half a dozen potential sites later to become our number one of our sites of the main complexes we should go to explore. But for the demise of Glynn this journey would certainly never have occurred, not at least as it was proposed to me because as director of the National Museum of Kenya, Richard wanted to set up an archeological program in West Turkana as they have done in Koobi Fora. I have little doubt I was hardly the first one to have made this trip, only to be offered the same propositions. I still wonder almost 40 years later how I could have been the only one to accept the deal. My first impressions, however positive they may have been, were still far below the true archeological potential of the West Turkana Plio-Pleistocene sequence. I was able to verify it quickly because in 1987 and 1988, I spent a month with Kamoya and Richard's team to do test trenches in those sites and all were positive. Of course, it took me some years to set up the program and create the West Turkana Archeological Project. Richard had left the Museum for the wildlife. I had to finish working in Isenya, et cetera. 

Although I was never allowed to tell or show my gratitude, no need to say that Richard has offered me the most extraordinary field and in my opinion, any early stone age archeologist could have dreamed about. I am not sure what he was expecting in doing so, but I like to think that he was quite happy with the results. And I'll leave you now with Sonia to tell you the rest of the story. So thank you for Helen. So, I'm back with me now and there are several dozens of early stone age sites have been discovered in West Turkana over 30 years. Probably one of the richest region of East Africa, if not of Africa for Plio-Pleistocene archeology. All are very well dated thanks to the work of Frank Brown and also Craig, unless Craig, you contradict me. But I think they're all extremely well dated. Some of these sites have been exhaustively excavated, some have been only tested, some are still under excavation. So as promised, I will now review only three of the major discoveries that we made with the West Turkana Archeological Project. I'm going to use the word WTAP because it's quicker than West Turkana Archeological Project. 

So, the first site that you probably have heard about, and I should say sites, they are two, are located at Lokalalei area. The sites when they were found were the oldest older ones found in Kenya at the time. Now it has changed oldest Oldowans found in Kenya. You can see the site of Lokalalei 1 on top with Dr. Mzalendo Kibunjia, the director of National Museums of Kenya, excavating it under the supervision of Helen. He did his PhD actually on stone tools from local Lokalalei 1. Then down here you have a picture of Lokalalei 2C a site that is extremely restricted geographically, but that was extremely rich. These two sites were studied compared and announced in 1999 in Nature, it's the beginning of a long story with Nature. The remarkable aspect of the stone tool technology at Lokalalei 2C is its complexity. So, we always believe before Lokalalei was found that the Oldowan was a very simple rudimentary technology, a couple of choppers, a couple of flakes removed from them and basically that's it. With Lokalalei Helen demonstrated that the two makers here were able to produce a lot of flakes, high productivity of flakes from one core, and this is an example from refit number 33.

There are a lot of refit at the site where tool makers were able to remove over 50 flakes with eight series of removals produced from the same flaking surface. If you want more details, of course you can refer to the subsequent publication by Dolan and Roche. So, I promise I'm not going to go much further with technological aspect on stone tools and I'm going to switch to a second major discovery that was made some years later at the site of Kokiselei 4 1.74 million years, which is for now the earliest Acheulian not very far in age with some Acheulean from Ethiopia. Also published in nature in 2011 and as you can see, this beautiful artifacts look could make you think of hand axes. So, we have here the beginning of bifacial knapping symmetry, but with a technique and methods that are not yet completely technically master. Pictures on top is our colleague for the one who know her Frida Nkirote when she was a student excavating here at Kokiselei 4. She I think, and until recently was the director of the British Institute Eastern Africa. 

Jump very quickly to the third and most recent major discovery that happened with the West Turkana Archeological Project, which is the Lomekwi 3 discovery. I guess many of you have already heard about this discovery maybe with some of our talks. So, we found the site, I remember like it was yesterday, the morning of July 9th, 2011. The WTAP team was surveying new outcrops, new outcrops for archeologists. Archeologists had never been in this area of Lomekwi. Samuel Ekodi, local Turkana that you see here with whom I've been working for many years, first spotted several large rocks on the surface with distinct fractures. We realized quickly that we were dealing with something very special. The stones were unusually large, nothing compared to what I was used to see at other sites, but they had nice and pretty clear fractures from knapping. So in 2011 we started test trench and the following year we started an excavation with the support of the National Geographic and we found more stone tools in situ. After many days of thinking I had lost Craig because he was running and going in all the outcrops around the site. Craig came back with a date for that site of 3.3 million. To this day, Lomekwi 3 is the oldest site ever found. 

Coming back to Richard a little bit and with what I learned from his technique for survey decades ago, and especially from the slides that I've seen from Louise talk, I would like to mention that even if we didn't use camels to survey this area, this new area in Lomekwi, we still used a very simple map for the survey by foot. Map that you see here on the left for you with targeted area of specific ages and we had then divided the outcrops in squares to be as systematic as possible. We had printed images from Google Earth, we had a giant binder every day we were selecting a new area to survey, and it works perfectly for us. As mentioned by Louise, this zone was already known by paleoanthropologist fossil hunters because it had already produced the fossil skull of Kenyanthropus platyops discovered by Meave and her team a few years ago. And yes, I know Louise, that you had spotted some of these stone tools on the surface. This is why you're part of the publication. So, we announced a discovery in 2015, we presented a preliminary description of the artifacts in 2015 in Nature. 

The site is still under excavation. We are progressing very slowly. The sediment is extremely hard, sorry. But we have now an excavated footprint of more than 700 square meters and a total of 273 lithic artifacts excavated or collected on the site surface and a little bit more of 100 faunal remains that also have been excavated. A series of publications are in preparation we are waiting for some very detailed analysis so stay tuned. There will be a couple of nice data published soon on the Lomekwi artifacts, but also on the bones that we have associated with the artifacts. Richard and Meave came to see the site and not easy for Richard it's quite far away, it's a remote place. He came to see the site a few days after we had uncovered a good number of artifacts in situ. He was of course extremely happy. He stayed for a long time, but of course he wanted to check by himself. I have to say also that it's the first time that I had a decent conversation with Meave about stone tools who had always said to me, ah, fairytales, fairytales, you archeologists, fairytales with your stone tools. You can't say anything. How can you say anything from a rock. 

That day and through these years, we still have very good, interesting conversation with Meave about stone tools and what they can tell us and how we can tell the thing we are telling you about when we talk about stone tools. I was very pleased to see that she mentioned Lomekwi 3 artifacts in her book Sediments of Time. So yesterday when I was finishing my presentation, I was not sure if I would inflict you a lot of pain in detailing every single of the stone tools and the technology of them and how they were made, et cetera. And I decided not to do it of course, but still a little bit about what the Lomekwi 3 stones say to us, and I'd be very brief. So, because it is the oldest by far the Lomekwi 3 site is extremely significant. We have only one so far. I'm desperate to find more and maybe we have found more, but this is also something I cannot talk about too much today. But we have to do with what we have, and the site provide the first glimpse of something that was completely unknown before we found the site. 3.3 million years ago someone,  a group of hominins, one hominin, one skilled one we don't know started to intentionally make things that didn't exist before.

And this long before our genes. So Lomekwi 3 disapproves with other discoveries the longstanding assumption since Mary and Louis Leakey that Homo habilis was the first toolmaker. For the first, for some time, sorry, Lomekwi 3 in fact was kind of expected. Since the 90s there was an increasing openness to the possibility of toolmaking before 2.6 million years, which was the age of the earliest site, then known and consequently by hominins other than our own genes. A few years before we discovered Lomekwi 3, the discovery of cut mark bones in Ethiopia, Dikika suggested the possibility of hominin use of stone tools for cutting by Australopithecus afarensis appearance at 3.4 million years. But unfortunately to date, there is no evidence for stone tool making in Dikika. So Lomekwi 3 is so far the only site opening up the possibility of tool making by hominins other than Homo before 3 million. We don't know who were the tool makers at Lomekwi. We don't know which species, which species Kenyanthropus platyops was present in the area West Turkana at the site, one kilometer away from our site. Australopithecus afarensis, Australopithecus deyiremeda are also found from around this period, Yohannes you have a talk about this on Monday and probably as you said, others are yet to be found. 

Perhaps it is now reasonable to consider that all of the species made and used stone tools, in any case, stone tool making happen with species with a relatively small brain. And indeed, given how common tool use is in other extant primates such as chimpanzees, we should consider that stone use might have a very deep prehistory. Perhaps back to and maybe before our evolutionary path diverged. What we know for sure is what we can read on the stone tools and the technology at Lomekwi 3 is different from what we see during the Oldowan. The size of the blocks or is a first major difference. We are dealing here with what I call mega-cores, huge, mid-sized 15 centimeters, very heavy ones, very bulky not the smallest blocks, medium-sized blocks that were used for the Oldowan. And of course here I talk in generalities, not in exceptions. We have large blocks for the Oldowan but what is striking with Lomekwi 3 is that we only have large blocks nothing small. Flakes produced can be for the first one, of course very large, but we have also smaller size all sizes. 

This gives me the opportunity to insist on the fact that the Lomekwi 3 technology is not only a pounding technology. These things were not used only as pounding tools if ever they were by the way. The major goal for the Lomekwian stone tool knaps was to create flakes. So, it's a flake-oriented technology like the Oldowan but with flakes that were produced using large blocks and with special techniques that we call on anvil percussion techniques, bipolar techniques of passive hammer techniques, which is different from the major technique that we recognize during the Oldowan, which is the freehand percussion technique. Doesn't mean that these large blocks were not used as pounding tools too. They have a lot of marks, they have a lot of pounding marks, percussion marks, but most of the marks that we see on them for now, we have related them to the techniques used to make them, bipolar percussion technique, not to any utilization as pounding tools to pound bones or any other organic material. 

So indeed, there had been important development in the archeology of West Turkana, the archeology of Turkana since Richard and Kamoya spotted the first stone tools in Turkana. I always wondered if Richard, Meave and Kamoya would've gone to Lomekwi if they would've seen them. Not easy to see them, not easy to recognize them. It takes a lot of expertise to recognize them believe me. Now we know what they look like, so it'll be hopefully a little bit easier to find more. But when you don't know what you're looking for, well it's when it's extremely difficult to identify them. There is still a lot of unknown. The more we find the more questions we have. Burning questions, tons of questions about Lomekwi 3, but also in general about the earliest technologies in the Pliocene. The potential of the region, and I'm only talking here about West Turkana is huge. It will occupy me for the rest of my career and I'm now training young people to take over, for example, what could have caused hominins to start knapping tools? We still don't know. And this is a discussion I had with Richard many times and we probably never know. It's going to be difficult to know that. When was the first flake detached, are we going to recognize this first flakes in the landscape? 

We can get closer to answer these questions in looking for most sites and Oldowans not to forget that Lomekwi 3, as I mentioned earlier, is one site for now we have only one site. Well, we have something else, but I can't mention it now. So can we find more of this image? That's what we are looking for. Can we find all the Oldowans? How far can we go back in time? This is what waits for us in the field in the coming years. I would say that the immediate impact of Lomekwi 3 has been to reinvigorate archeological research to push boundaries, to search in the places and in the timescales where the archeological record is currently unknown. Richard was very proud of that. We don't know anything between of the relationship, if there is any between the Lomekwian and the Oldowan. In West Turkana for example, we have no sites between 3.3 and 2.3 million years old. There is a lot to be done. Lomwekwi 3 is like a teaser. As the next step for us we need to focus on Pliocene deposits in Turkana and more generally across East Africa and beyond. I also hear people telling me to go look into the Micoene, why not invite me.

So, it is one of the WTAP goal in the future to search for all the tools and survey more relevant deposits in West Turkana. We looked around Torpenawi for example, nothing only bones, but we need to keep in mind that this could be very challenging for many reasons. But one of the reason is that it's very possible that this behaviors were very rare, so possible that we will not be able to identify any older stone tools in the environment. With better technology, Bob, your maps, your iPads with drones, with lidar imagery that we're going to use soon. We should be able to do a good job if the sites are there. And I'm thinking in particular for the areas that are not easily accessible to us. I am not a huge fan of camels safaris myself, although I've never tried, I have to be honest, donkeys I did in Ethiopia, but not camels. But I heard that a helicopters could be also a great improvement for survey. And this is a special message for Lawrence and Dino. This is a picture of 

This is a picture of me, and Jill and Marilyn and the pilot of the helicopter taken in January, last January at TBI Turwel where I had the extreme chance to take our donors and the international board to the Lomekwi site with the helicopter, which was what, a 20 minute, 20 minute trip fantastic! And I had never seen the site and this area from the air except with the drone that we are using. So it was really a fantastic experience and I have to say that it will definitely could be a very interesting tool to have a larger view of areas that we would like to explore. 

So just to conclude, it is a lot of work that we need to do. I think it's the same for all of us anyway, but it is also extremely exciting. I would like to say also that we cannot mention the hard work and dedication. We cannot not mention, sorry, the hard work and the dedication of the wonderful cohort of Kenyan students that are always coming with us that we have welcome at TBI over the years. And were either finishing their master’s with TUC, Turkana University College or about to start their PhD. Dino mentioned a couple of them, three of them on Monday. I have to add on that list. Medina Lubisia was going to come to a PhD with me very soon. The only archeologist of the cohort. So Richard's vision is in this too. And we have the duty to train the next generation of paleoscientists, the next Kenyan leaders in the field. We already have a good group, but it's our duty to of course, continue and do that because after all, we all stand on the shoulders of giants. Thank you very much.

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