In late May, Paul Sereno was in town to talk at the 2008 conference titled, ‘Integrating Evolution, Development, & Genomics.’ He was invited to also give a talk titled, “Living Lakeside in the Sahara: A Chronicle of Holocene Adaptation,” to the Primate Biology Group. I eagerly attended. Paul Sereno, if you don’t know, is primarily a dinosaur paleontologist and geologist. And a really well known one at that. He’s discovered around 10 or so new dinosaur species.
But, in 2000 while on a excavation for dinosaurs and giant crocodiles in Niger, National Geographic photographer, Mike Hettwer, stumbled upon a Neolithic graveyard. Sereno shifted his search for dinos to studying these bodies and the artifacts associated with them. He discussed his finds in his talk.
It was so inspiring to be there, and I’m not alone in sharing this sentiment. I was attending the talk with a couple of friends, and they also felt the same way. The clarity and enthusiasm with which Sereno explained the site and his work was impressive — I’ve rarely seen someone so excited to explain so much material. Sereno’s definitely got a reason to be enthusiastic — he has what is now most likely the largest collection of Early to Mid-Holocene bones ever discovered at a single site in Africa.
After the talk, I got a chance to have a one and one with Sereno. He let me know about his time frame and publication plans. I’m happy to see that everything has come to fruition. Published today, in the open access journal PLoS One is Sereno et al.’s analysis of the site, “Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change.”
In the paper, Sereno and team describe the paleoecology of the site and climatic change. They include their interpretation of the burials and associated artifacts. I’ll do my best summarizing the piece in this blog post, but I really recommend you read this gem for yourself. It is open access and well written — you don’t have really any excuse not too.
This site has been called Gobero, after the local Tuareg name for the area. About 10,000 years ago (7700–6200 B.C.E.), Gobero was a much less arid environment than it is now. In fact, it was actually a rather humid lake side hometown of sorts for a group of hunter-fisher-gatherers who not only lived their but also buried their dead there. How do we know they were fishing? Well, remains of large nile perch and harpoons were found dating to this time period.
Of the 67 burials excavated, five of them date to an occupation span from 9,750 to 9,500 years ago. That’s 250 years or so. Looking at photos of the field site, it is hard to believe these prehistoric people got comfortable in Gobero. They began making pottery and ritually burying their dead. One of these guys, G3B8, is a 2 meter tall dude (that’s like 6 feet 6 inches!). He’s pictured below, buried rather utilitarian, with hands covering his mouth and crossed feet, just as he was found:
G3B8 is not alone in his stature and robustness. There other burials, both male and female, from this time frame are of similar height. These Early Holocene hunter-gathering fishermen also have characteristic skulls — long and low, with a unique occipital bun and broad nasals. These features aren’t restricted to only adults, in fact, juveniles as young as 4 years exhibit similar traits which are not shared by the later inhabitants of Gobero. These bodies were tightly bound when buried.
Around 6200 B.C.E (8,200 years ago) Gobero began to resemble what we see today. The paleolake dried up, and these tall, robust inhabitants hauled out. The youngest early-Holoecene burial dated to 6210 B.C.E. This regional climate change persisted for about 1,000 years, correlating to climatic deterioration across the Chad Basin and linked to the chilling of the North Atlantic.
The return of humid conditions came about immediately after this arid interruption. The lake refilled, and plants, animals and people moved back to Gobero. These favorable conditions persisted for much longer than the early Holocene occupation, roughly 2,700 years. The new settlers were anatomically much different from their predecessors. For starters, they are shorter. They’ve got tall, narrow skulls, with long faces. This guy, dubbed G1B11, is a mid-Holocene adult male dating to around 4,645 B.C.E. is a good example of the different morphology:
To better illustrate the differences between the robust, early occupants and the latter, gracile ones. Check out this comparison. On the left is a 9,500 years old skull of this mature male. The eye sockets are square, the cranium is low and check out those nasals! On the right is a 5,800 years old skull of a young adult. While not as mature as his 3,700 counter part, you can see the anatomical differences for yourself — a much taller cranium, look at the forehead.
7 of 35 burials excavated from the mid-Holocene occupation were buried with artifacts. I remember Sereno showing us a photograph of an individual buried with a turtle shell underneath him. I didn’t catch the specimen number at the time, and now found out that guy is G1B11 — pictured above. You can see in the middle image the carapace functioning as an eternal bed. The mid-Holocene occupants were much more symbolic than the early Holocene individuals. They buried their dead with more elaborate artifacts, such as this 11 year old girl (G1B2) who is wearing an upper-arm bracelet carved from the tusk of a hippo. She’s believed to have died around 4,835 years ago.
Why were these people burying their dead with beads, bracelets, and on turtle shells? Sereno et al. suggest that the latter occupants were more pastoralists and agriculturalists — because archaeological evidence for grain and remains of domesticated cattle are present in the midden from this time period. Their gracile frames support this lifestyle, as well. Additionally, curious looking fine-grained green rocks were used to make points, scrapers and adzes from this time period. This rock isn’t found in Gobero. Actually, this feldspar rock came from Alallaka — a prehistoric rock quarry about 160km north of Gobero. The relaxation from gathering and hunting for food allowed for people to develop new skills, such as jewelry making and symbolic burials — even trade their skills for green rocks from the north.
So who were these people?
Sereno et al. did a principal components analysis of craniofacial dimensions of the skulls from both periods and compared them to Late Pleistocene to mid-Holocene populations from the Maghreb and southern Sahara. The early Holocene occupants are similar to remains from Maghreb Capsian, Maghreb Iberomaurusian, Mali, Mauritania. The mid-Holocene occupants are unlike any other population tested. That doesn’t tell us much about who they were.
So Elena Garcea, a specialist in African archaeology from this period, analyzed the material culture. She believes that the bone harpoon points and hooks, as well was the dotted wavy-line, zigzag ceramic exhibit attributes of the Kiffian people. Kevin MacDonald described the Kiffian technology, one that specialized in harpoons and microliths, in the text “Archaeology and Language.” Several other publication also support this claim. On Sereno’s website, there are more photos of the bone harpoons and pottery. I don’t have any examples of Kiffian artifacts to compare, so I’ll just trust that Garcea and Sereno got this identification.
The mid-Holocene occupants are believed to be Tenereans. Their affinity for green feldspar and the small projectile points as well as the disc knives characterize the Tenerean material culture. An example of Tenerean style projectile points from Gobero is below: IMAGE REMOVED AS PER MIKE HETTWER’S REQUEST.
If you’re not completely floored by the wealth of archaeological and anatomical material from Gobero, let me share with you the Tenerean triple burial. The triple burial includes a female, presumably the mother, laid to rest on her right side who died somewhere around 5,300 years ago. Facing her are two children (ages 8 & 5 years old) and buried on their left side, interpreted as her children. These people were buried with their arms and legs around each other and holding hands. Abundance of pollen residues underneath them suggest they were buried on a bed of flowers. Multiple burials like this, and in this condition are rare. Furthermore, this is first triple burial ever discovered on Africa.
Sereno did not excavate these individuals like a normal archaeologist would. Instead, being a dinosaur specialist, he jacketed the remains.
You’re probably thinking, “Sacrilegious technique! He shoulda used brushes and dental picks, removing each bone and shipping them off for study in the lab.” But had he not done so, burials like the triple burial would have not survived excavation — the extreme heat of the Sahara has made the bones exceptionally fragile. That’s why having a multidisciplinary approach to doing this sorta fieldwork works. And I commend Sereno for taking these measures to preserve the bodies and site.
This publication has shown us very eloquently how important Gobero is to our understanding of climate change and prehistoric peoples and archaeology of the Sahara. As more and more of Gobero becomes exposed and weathered, more and more of it will be lost to time if we do not support Sereno’s research. Hettwer has documented the impact 5 years has made on one such exposed skeleton:
I’ve mentioned before only 67 burials were excavated. There are at least 182. Gobero needs to be preserved, for its wealth of evidence and the cultural heritage it provides Niger.
- Sereno, P.C., Garcea, E.A., Jousse, H., Stojanowski, C.M., SaliÃ¨ge, J., Maga, A., Ide, O.A., Knudson, K.J., Mercuri, A.M., Stafford, T.W., Kaye, T.G., Giraudi, C., N’siala, I.M., Cocca, E., Moots, H.M., Dutheil, D.B., Stivers, J.P., Harpending, H. (2008). Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change. PLoS ONE, 3(8), e2995. DOI: 10.1371/journal.pone.0002995