Lions of the mammoth steppe

This post is by Erik Ersmark,  lead author of the recently published paper “Population Demography and Genetic Diversity in the Pleistocene Cave Lion“. He is a PhD candidate in the Department of Bioinformatics and Genetics at Stockholm University and the Swedish Museum of Natural History, Stockholm, Sweden.

Today’s African savannah boasts an impressive biodiversity of large mammals that is unique in the modern world. However, this kind of ecosystem was not always restricted to the grasslands of Africa. Far back in time a similar steppe stretched across the entire Eurasian continent all the way from Spain to Alaska, a huge northern savannah inhabited by huge mammals. But although similar, it was at the same time quite different: instead of wildebeests, buffalos and elephants, this steppe was home to bison, aurochs and woolly mammoths. Its fauna was well adapted to the prevailing dry and sometimes quite cold conditions, in many cases to such an extent that these animals were only found in this specific environment.

562px-Lions_painting,_Chauvet_Cave_(museum_replica)

Cave lions of Chauvet Cave, France

The vast mammoth steppe did not only contain mammoths, horses and other grazers. Preying on the large herbivores were large predators like wolves, sabretooth cats and lions. The lions were of a robust type, slightly larger than their modern counterparts, and although recognized as lions from their remains, no one today knows precisely what they looked like. We know that humans did encounter them far back in time, since they in some cases depicted the lions and thereby provided us with some hints of their appearance. Lions are in fact frequently occurring in Palaeolithic art, perhaps most prolifically and famously so in the cave paintings from the Chauvet cave in France, dating back some 30 thousand years. Cave sites like this have sometimes also contained the actual remains of lions, which has led to the somewhat misleading name given to them – cave lions.

Along with so many other large bodied “cave animals”, the cave lion did not survive into historical times. They went extinct at the end of the Pleistocene era around 14,000 years ago, and around this time the entire mammoth steppe was also fading and it was eventually transformed into woodland and barren tundra.

SAMSUNG

Erik Ersmark extracting DNA

In order to better understand the population dynamics of the cave lion, we analysed remains gathered from across the former mammoth steppe. We specifically focused on north eastern Siberia, which in the Late Pleistocene was part of Beringia – a vast northern landmass bridging Eurasia and North America. Since the ground is permanently frozen throughout most of this region, the remains found there are usually very well preserved, enough so that it is even possible to extract DNA from them. Together with radiocarbon dating, this DNA provided us with data on how the genetic diversity had changed over time. After all analyses had been performed, the results could give us a glimpse of what had happened to the cave lions of Beringia.

What the results showed was something already suggested in a previous study by Barnett et al. (2009); that the Beringian cave lions had suffered a decline, long before they eventually went extinct. The genetic diversity clearly showed a pattern of a bottleneck having taken place far back in time. By running powerful simulations on our data together with those from the previous study, an estimate was obtained of a decline in population size starting almost 50,000 years ago. This decline seemed to have been both severe and long lasting, because it was not until a few thousand years before its final extinction that the cave lions started to recover.

lion_sample

A cave lion jaw and teeth sampled for this study

The question we were left with was why this bottleneck had taken place. What was the underlying cause or causes? What was more, many other large mammals also seem to have suffered declines in Beringia over this time period. This period did coincide with the expansion of a new kind of predator across Eurasia – modern humans. However, there are so far no reliable human traces of that antiquity (the start of the bottleneck) from inside Beringia, which makes us less likely as suspects. Our results open up for many interpretations, but also for many further studies of the lost and diverse fauna of the mammoth steppe.

You can read the full article, completely free, in our latest issue of Open Quaternary.

References:

  1. Barnett, B. Shapiro, I. Barnes, S.Y.W. Ho, J. Burger, N. Yamaguchi, T.F.G. Higham, T. Wheeler, W. Rosendahl, A.V. Sher, M. Sotnikova, T. Kuznetsova, G.F. Baryshnikov, L.D. Martin, R. Harington, J.A. Burns, A. Cooper, Phylogeography of lions (Panthera leo ssp.) reveals three distinct taxa and a late Pleistocene reduction in genetic diversity, Molecular Ecology, 18 (2009), pp. 1668–1677
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Looking into the Horse’s Mouth: How cementum can tell us about age and season of death

This post is by Haskel J. Greenfield, lead author of the recently published paper “Estimating the Age- and Season-of-Death for Wild Equids: a Comparison of Techniques Utilising a Sample from the Late Neolithic Site of Bad Buchau-Dullenried, Germany“. Greenfield is a Professor in the Department of Anthropology, University of Manitoba, Canada.

The genesis of this study was an odd email request from a German colleague (Karlheinz Steppan) to see if someone was willing to conduct a dental cementum analysis of wild equid specimens from the Neolithic settlement at Bad Buchau-Dullenried, Germany. In my usual exuberance (and naiveté), I thought that this was an interesting opportunity to learn about horse cementum, while collaborating on the analysis of Neolithic material (always a passion of mine). I had already done previous cementum work with my students on sheep and goat. How difficult could it be to do equids, I thought. Well, I should have spoken with my good friend and colleague, Arianne Burke at the University of Montreal, before I embarked on what became a six year quest. On the surface (pun intended!), it was actually much easier to thin-section equid teeth than sheep and goat. Equid teeth were larger and the cementum layers longer and thicker. I thought it should be a “no brainer” to thin-section them and do the seasonality and ageing analyses.

horse skull

A horse skull. Image from Wikipedia.

In fact, nothing proved to be simple other than recruiting Collin Moore (at that time, a MA student in Biological Anthropology at the University of Manitoba; currently, finishing his PhD at the Max Planck Institute for Evolutionary Anthropology, Leipzig) to help me with the project. Collin was a particularly apt collaborator for this research since his specialty was the analysis of dental microstructures (albeit in humans) with new digital technologies.

Once Karlheinz had sent us the specimens, we began to prepare our documentation and analytical protocol. The thin-sectioning stage went relatively easily once we had selected, documented, and prepared the specimens. Once the slides were ready for analysis, we began by independently examining them in a traditional light optical microscope. Of course, the results were contradictory. Then, Collin suggested that we use the new digital microscope that my colleague, Robert Hoppa, had installed in the Bioanthropology Digital Image Analysis Laboratory at the University of Manitoba. This opened up a wealth of visual and data analytic techniques for mapping and analysing the cementum increments. The problem was: how to interpret the results? This is where the science and the art begin to separate in our discipline. The scientific techniques were there, but the interpretation becomes the art. It is in the art that all the techniques and analysts begin to differ, we discovered.

horse teeth

Four of the samples used in the study. From Greenfield et al. 2015.

Given our initial consternation at having come up with different results for ageing and season of death of the samples, we decided to use the specimens to test the various ageing and seasonality techniques for equids that have been published and become widely accepted by zoologists and zooarchaeologists. This forced us to backtrack and begin the analysis again, without any preconceptions. First, we analysed the remains using traditional veterinary and zoological techniques, such as incisor tooth wear. Then, we tried using Marsha Levine’s commonly applied cheek tooth height formula. Finally, we began to analyse the specimens using well-established and age verified Arianne Burke’s protocol for dental cementum. These were then compared with our results from the new automated technology.

The results were surprising—and disconcerting. The tooth eruption and wear and crown height measurement techniques yielded the lowest age estimations and were not useful for seasonality determination. Simply based upon comparison with modern tooth eruption analogues, the age of any individual analysed in this manner would be underestimated. The manual increment counting age estimation technique yielded wider variation in age estimation than the other techniques, and older age estimation than tooth wear/eruption or crown height measurements. The line histogram technique yielded narrower range of age estimation than manual observations, but still yielded a slightly older age range. The automated age estimation technique yielded the narrowest range of age estimation. However, age values were slightly higher than with the manual or line histogram results.

In contrast, all of the thin-sectioning techniques yielded a similar range for the season-of-death of the animal. However, we found that it was most efficient to use the automated technique to pinpoint when in the cold or warm seasons that the specimen may have died. Overall, the automated technique was by far the most efficient in terms of time and effort, and the most accurate when comparing teeth from the same individual.

The automated technique provides the narrowest age- and season-of-death range. It is the most effective, as well as the most efficient in terms of time and energy, technology to use. The application of the new digital technologies is the way out of the intellectual trap of “which technique is superior” because it removes much of the “art” (or human observer variability) from analysis. What do we learn from this experiment? The most important result is to never simply to use one technique of analysis. Which technique is closest to the truth? Who knows, but we learned a lot while doing it!

You can read the full article, completely free, in our latest issue of Open Quaternary.

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Launching Open Quaternary

Several months ago, we introduced Open Quaternary in a so-called “soft launch”. All the odds and ends had been settled with our open-access publisher, Ubiquity Press, our website went live, and we began to solicit paper submissions. We also began a Facebook page, started tweeting at @OpenQuaternary and Simon Goring, an editorial board member and the research blogger behind downwithtime, graciously got this blog off the ground.

oqd

The new Open Quaternary website, highlighting recently published and top articles.

 

Last week saw our official launch, with 3 diverse publications representing our research and methods paper categories on a brand new, redesigned website. In addition, we, the editors in chief, included an editorial announcing the launch and papers. In just two days of launching, we had over 1000 sessions and over 2700 page views. Moving forward, we have a number of submissions in the review process, including papers in our public engagement and data categories as well as a special collection based on conference proceedings. In the meantime, we will be sharing a series of blog posts on our published articles here at the OpenQuaternary Discussions blog, so watch this space!

Of course, if you have not yet read the editorial or articles, you they are available, free, and can be viewed or downloaded at openquaternary.com. We are currently accepting paper submissions on a rolling basis.

 

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THE ADVANTAGES OF TAKING A CHANCE WITH A NEW JOURNAL – OPEN QUATERNARY

Simon Goring is a member of the editorial board and an author of an accepted article at Open Quaternary.  Here he discusses his experience participating in the editorial process in anticipation of the journal’s launch issue, available online in March 2015.

Figure 1. Neotoma and R together at last!

We (myself, Andria Dawson, Gavin L. SimpsonEric GrimmKarthik Ram, Russ Graham and Jack Williams) have a paper in press at a new journal called Open Quaternary.  The paper documents an R package that we developed in collaboration with rOpenSci to access and manipulate data from the Neotoma Paleoecological Database.  In part the project started because of the needs of the PalEON project.  We needed a dynamic way to access pollen data from Neotoma, so that analysis products could be updated as new data entered the database.  We also wanted to exploit the new API developed by Brian Bills and Michael Anderson at Penn State’s Center for Environmental Informatics.

There are lots of thoughts about where to submit journal articles.  Nature’s Research Highlights has a nice summary about a new article in PLoS One (Salinas and Munch, 2015) that looks to identify optimum journals for submission, and Dynamic Ecology discussed the point back in 2013, a post that drew considerable attention (here, here, and here, among others).  When we thought about where to submit I made the conscious choice to choose an Open Source journal. I chose Open Quaternary partly because I’m on the editorial board, but also because I believe that domain specific journals are still a critical part of the publishing landscape, and because I believe in Open Access publishing.

The downside of this decision was that (1) the journal is new, so there’s a risk that people don’t know about it, and it’s less ‘discoverable’; (2) even though it’s supported by an established publishing house (Ubiquity Press) it will not obtain an impact factor until it’s relatively well established.  Although it’s important to argue that impact factors should not make a difference, it’s hard not to believe that they do make a difference.

Figure 2. When code looks crummy it’s not usable. This has since been fixed.

That said, I’m willing to invest in my future and the future of the discipline (hopefully!), and we’ve already seen a clear advantage of investing in Open Quaternary.  During the revision of our proofs we noticed that the journal’s two column format wasn’t well suited the the blocks of code that we presented to illustrate examples in our paper.  We also lost the nice color syntax highlighting thatpandoc offers when it renders RMarkdown documents (see examples in our paper’s markdown file).  With the help of the journal’s Publishing Assistant Paige MacKay, Editor in Chief Victoria Herridge and my co-authors we were able to get the journal to publish the article in a single column format, with syntax highlighting supported using highlight.js.

I may not have a paper in Nature, Science or Cell (the other obvious option for this paper /s) but by contributing to the early stages of a new open access publishing platform I was able to change the standards and make future contributions more readable and make sure that my own paper is accessible, readable and that the technical solution we present is easily implemented.

I think that’s a win.  The first issue of Open Quaternary should be out in March, until then you can check out our GitHub repository or the PDF as submitted (compleate with typoes).

This post originally appeared on downwithtime.

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A view from the field.

Since we’re half a year away from the traditional academic time period known as “field season” (at least in the Northern Hemisphere), I’ve been thinking a lot about being out and about.

For many Quaternary scientists field work involves coring in one form or another.  You name it, we’ll core it.  Corals, trees, lakes, swamps, bogs, forest floors, ocean floors, we’ll section pack rat middens (crystalized urine), we’ll drill through guano piles, stalagmites, stalactites, glaciers. . . and I’m pretty sure there’s others that I’m missing.  Pictures of pollen coring expeditions are iconic images in paleoecology.  Most of us who have spent time on the ice or in two lashed together dinghies (or fancier digs!) can immediately relate to the pictures, but, unlike the stratigraphic diagrams that get produced afterwards, these pictures can be easily lost, and yet they represent a critical part of our investigations.  They link our scientific discoveries to a specific place and time, they provide a snapshot of paleoecological geneology that publications can’t capture.  Not everyone on the coring platform gets authorship (although they should be acknowledged!).

With that in mind I posted a note on the PALEOLIM mailing list looking for coring pictures and got a great response and I thought I’d share some of them with you here.

Grimm_Brush_Lake_MT_Coring

Eric Grimm sent this one to me.  A winter coring expedition at Brush Lake, MT near the North Dakota border.  Given the location this could be late spring (!).  Pictured here are Jeremy Wolpert (formerly a grad student at WVU, now a Senior Geologist in Texas), Kendrick Brown (now with the Canadian Forest Service), Alex McLeod (kneeling, PhD student, Monash University Australia), Joe Donovan (Geology prof., West Virginia),and Eric Grimm (Illinois State Museum).

Baikal Archeological Project 2006 (University of Alberta).Ile d'Olkhon.

This picture was taken by Marc Roussel and it comes from Anson MacKay.  Taken on Shara Nu, Lake Baikal.  Anson’s posted previously about Lake Baikal on the OpenQuaternary blog. On the left is Dr Dustin White (University of Southampton) and in the middle standing up is Dr Alexander Shchetnikov (Institute of the Earth’s Crust), while bending down next to Dustin is Ewan Shilland (University College of London) and on the far right is Anson MacKay.

I have a bunch more, and will post them as we figure out what to do with them!  In the meantime if you have more coring photos, please send them to us along with the list of people in the photos, and, if possible, publications that came from that coring expedition.  We’d love to start compiling these in a more formal way.

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Term ends, research begins?

Kirsty Penkman is a Senior Lecturer in the Department of Chemistry at the University of York, UK.  Se is a member of the Editorial Board for Open Quaternary. Her research expertise is in analytical and environmental geochemistry and biomolecular archaeology and she runs the North East Amino Acid Racemization (NEaar) dating facility. As many of us in the academic world are finishing our semesters this week, she shares some of the challenges-and offers some solutions-for staying productive year-round.

The frenzy of the last few weeks of term has passed, the corridors are quieter.  Blank spaces in my diary don’t get immediately filled with meetings.  The list of daily tasks has morphed from short-term fire-fighting urgent deadlines into lovely longer-term projects that I am excited about getting my teeth into.

Being an academic is a joy, not only getting to research a subject you love, but also to teach it, to help others uncover those intriguing mysteries and beautiful solutions.  But the nature of the academic calendar means that the first week after term ends does feel like the calm after the storm.  Long to-do lists are written, great plans are made.  But then the time zooms by….

kkro-cup-red-front

Looking back at my summer list (inspirationally entitled “long term summer thinking!”), only about half actually got done.  I had been so excited about my summer of research – coming back from maternity leave straight into the start of the academic year (and returning part-time) had meant that I hadn’t focused entirely on research for a long while.  So I had planned to use long summer days to analyse samples, sort out a backlog of data, write grants, write papers, re-jig teaching materials…the list goes on!  When I added up the number of full working days (not including conferences, etc.) that I had to achieve this in, I was horrified to discover I only had 17 free days over the 3 months.  Only 17 days!!

This meant that when I started back at the beginning of the Autumn term, I knew I had to make a change.  Something had to give – I couldn’t just keep putting my long-term research off until the vacations.  It was just the right time for me to take on board useful advice, and it happened to be the book “How to Write a Lot: A Practical Guide to Productive Academic Writing” by Paul Silva.  I romped through this in a couple of hours on a train-trip back from a meeting in October, and it was the wake-up call I needed.

writing

So the secret?  A very simple message – stop procrastinating!  I am one of those people who would say “I’ll write the paper / grant when I can find a clear day / week / month”; a “binge writer”.  Well, that never happens!  Silvia’s key message is self-admittedly obvious: you just need to:

  • set regular writing slots in your schedule
  • set goals for your writing
  • track your progress.

The philosophy is that the very action of writing has been shown to increase the frequency of your creative ideas, so writing breeds writing.  With the added bonus that if a nice long slot for writing does come along, you’ll be in a better state to take full advantage of it.  Never a fan of writing, one aspect which helped persuade me to give this a go was Silvia’s broadening of  the definition of “writing” – anything that contributes towards writing counts, so it could be sorting out data for a paper (as long as the data is also written up!).  For me, it was the right message at the right time.  I needed to change my writing mindset; instead of putting writing off for moments of inspiration or isolation, I needed to make time for it as part of my weekly routine.

I blocked out short periods of time in my diary to write; it was quite hard to find slots given I was in the middle of a heavy-teaching term, but I did manage to squeeze in 3 slots every week.  I have to admit I haven’t succeeded in keeping all of them (machine breakdowns, students who need to get data by a deadline, etc.), but my log shows me I’ve written for over 90% of the time I put aside.  Looking back at my diary for the previous term, much of that wouldn’t have happened if I hadn’t specifically set aside time.  As a consequence of starting this half way through a term (and therefore having to shoe-horn time into an already packed schedule), I have also discovered which periods of time aren’t productive for me, so I can organise my schedule for the future based on that valuable information.

I am definitely not the perfect finished article yet, but writing regularly has definitely worked for me.  It is often difficult to prioritise longer-term research when short-term externally-imposed deadlines abound, but it is one of the most important parts of our jobs, so I shall continue to keep my precious writing time sacrosanct.  I have learnt this lesson a bit late – one of the tips for grad students in the book is to start this type of writing schedule as early as possible, as it will make that goliath thesis more manageable.  And if you think you don’t have enough to write about now, go along to your supervisor and see if they have anything you can dust off and work on; I am sure you won’t be disappointed!

So now that I’m writing a lot (or at least a lot more than I used to), hopefully the division between “term ends and research begins” will be less evident.  Now I just have to learn to write good – sorry – better!

 

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The Summer Fieldwork Season II – The wilds of the Knersvlakte, Western Cape, South Africa

Teresa Steele is an Associate Professor in Department of Anthropology at the University of California, Davis, currently on sabbatical in the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. She is a member of the Editorial Board for Open Quaternary. She has research interests in modern human origins and zooarchaeology and field projects in France, Morocco, and South Africa. In this week’s post, she provides insights into her archaeological fieldwork in South Africa in 2014. This is her first ever blog post.

The ancestors of everyone living today came from Africa, but “Africa” is a big place, over 30 million square kilometers, so where did these ancestral populations live? How did they make their living? When did some of them leave Africa to populate the rest of the world? How did they support this expansion? And most importantly, WHY? These are the questions that keep me up at night – me and other paleoanthropologists studying modern human origins.

Figure 1. Trees lining the Varsche River, South Africa.  Photo credit: Theresa Steele.

Figure 1. Trees lining the Varsche River, South Africa. Photo credit: SNAP.

I am leading the Southern Namaqualand Archaeological Project (SNAP) with Dr. Alex Mackay (University of Wollongong) in the Western Cape of South Africa. The project is based along the Varsche River in the Knersvlakte [map], the quartz-gravel desert (whose name translates to gnashing, or grinding) is so named (as the story goes) because of the crunching sound carriage wheels made going over it (Figure 1). The region is part of the Succulent Karoo ecoregion, after its tiny succulent plants,  but it also preserves records of the past. Patches of the landscape are littered with stone artifacts, providing evidence of human activity deep in the past, when stone was the primary source of our technology and when the Knersvlakte provided more resources than today.

South Africa has benefited from a long history of archaeological research, and the southern and western coasts are well-known for their Late Pleistocene archaeological deposits including Klasies River, Blombos Cave, and Pinnacle Point. These sites have provided key data and fueled discussions about modern human origins.  The sites include early evidence for advanced technology and symbolism in the form of beads and engraved ochre, some of which is well documented by the TRACSYMBOLS project. Researchers, including Curtis Marean of Arizona State University, have argued that this region provided just the right mix of rich marine resources along with nutritious plant resources (in the form of geophytes) to promote the evolution of modern humans. Others, including Richard Klein of Stanford University, have argued that the record of human behavior from 250,000-50,000 (the Middle Stone Age) is less complex than the more recent Later Stone Age and Upper Paleolithic (which began 50,000–40,000 years ago). To better address these issues, we need a better understanding of the range of variation in Middle Stone Age behavior and especially how technology, subsistence, and demography varied with environmental context. In short, we need more sites from difference environmental contexts so that we can test these models of modern human origins.

Figure 2.  Lithics scattered on the landscape.  Photo credit: Theresa Steele

Figure 2. Middle stone age lithics scattered on the landscape. Photo credit: SNAP

One of the most common questions I am asked as an archaeologist is: “How do you know where to dig?” The decision about where to dig is influenced by research design, local contacts, and luck. Around 2008, I was looking for a new project – ideally, a Middle Stone Age site with faunal preservation outside of the well-studied coastal regions. My colleague Jayson Orton (ASHA Consulting; University of Cape Town; and University of South Africa) from my then current South African project (Ysterfontein 1, map from Klein et al. 2004) was targeting Namaqualand Later Stone Age sites for his dissertation research.  A few years earlier another mutual colleague (Royden Yates) had shown Jayson some shelters along the Varsche River which he had seen while surveying rock art sites.

Figure 3.  Closing up the pit.

Figure 3. Closing up after some great field work, with the team. Photo Credit: SNAP.

In 2008, Jayson and I went to visit the Varshe sites, where it was possible to see Middle Stone Age artifacts scattered on the landscape (Figure 2). In addition to the scattered lithics and surface material, there were three unexplored rock shelters. No matter what, someone was likely to be happy, and we would learn something from a project in the region. In 2009, Jayson, Alex, my graduate student Steve Schwortz, and I spent three weeks in the area testing the three rock shelters and collecting data on surface material. Two of the shelters yielded only Later Stone Age material, Reception Shelter (VR001) and Buzz Shelter (VR005), and the third site, VR003, yielded primarily Middle Stone Age material. We were all happy. Jayson continued to excavate Reception and Buzz, which formed the foundation of his PhD thesis. Alex and I have focused on VR003 with a four-week field season in 2011 (with my one-year-old in tow – fodder for another blog post!) and then again in 2014 (with my four-year-old staying home with daddy).

We targeted this region because it is currently located in a winter-rainfall zone desert. Despite the challenging environment today (the region receives only about 150 mm of rain per year), it was likely much wetter during past glacials, which increases the chances of finding traces of human behavior from MIS 6, 4 and/or 2. Human activity is especially poorly documented southern Africa during MIS 6 and 2, which is unfortunate because these stages encompass the establishment of Later Stone Age and early Middle Stone Age behavior, key periods for understanding modern human origins. MIS 4 is particularly interesting because two variants of the Middle Stone Age, the Still Bay and Howiesons Poort, are associated with it and may have been influenced by the changing environmental conditions leading up to MIS 4 and during MIS 4. Unique aspects of these two industries have played leading roles in discussions of modern human origins, because they are associated with early beads, engravings, and complex stone tool technologies.

Figure 4.  Lithics

Figure 4. Stone tools from VR003 including both Still Bay (a) and Howiesons Poort (b) variants.  Photo credit: SNAP

At VR003, we have found both the Still Bay (Figure 4a) and Howiesons Poort (Figure 4b) variants within a sequence that extends earlier and later. The stone artifacts show signatures of the region – quartz is the dominant material, which is not surprising given its abundance on the landscape. We find hints of other pre-Still Bay variant, which may link our site to others further south, and as well as some pieces that are unique (Figure 5).

Figure 5.  Unique pieces from VR007.

Figure 5. Two unique pieces from VR003. Photo credit: SNAP

VR003 also preserves vertebrate remains, unlike too many other Middle Stone Age sites. Zebra, wildebeest and hippopotamus support the interpretation of  wetter, and therefore grassier conditions during the cooler Late Pleistocene. One of the most surprising finds in the faunal assemblage is a few marine mollusks, particularly limpets; the site is ~45 km from the current coastline, which would have been even further during glacial times. Transport of marine shells over this distance hasn’t previously been documented during the Middle Stone Age, but it common during the Later Stone Age, including at VR001 and VR005.

We are very happy about one thing that we didn’t find this past season – bedrock, which means that VR003 is likely to continue to reveal clues about human evolution into the deeper past. We look forward to returning in 2015.

More reading

Chase BM and ME Meadows. 2007. Late Quaternary dynamics of southern Africa’s winter rainfall zone. Earth-Science Reviews 84:103-138. [link]

Chase BM. 2010. South African palaeoenvironments during marine oxygen isotope stage 4: a context for the Howiesons Poort and Still Bay industries. Journal of Archaeological Science 37:1359-1366. [link]

Jacobs Z and RG Roberts. 2009. Human History Written in Stone and Blood. American Scientist 97:302-309. [link]

Jacobs Z, RG Roberts, RF Galbraith, HJ Deacon, R Grün, A Mackay, P Mitchell, R Vogelsang and L Wadley. 2008. Ages for the Middle Stone Age of southern Africa: Implications for human behavior and dispersal. Science 322:733-735. [link]

Mackay A, J Orton, S Schwortz and TE Steele. 2010. Soutfontein (SFT)-001: Preliminary report on an open-air site rich in bifacial points, southern Namaqualand, South Africa. South African Archaeological Bulletin 65:84-95. [link]

Orton J, A Mackay, S Schwortz and TE Steele. 2011. Two Holocene rock shelter deposits from the Knersvlakte, southern Namaqualand, South Africa. Southern African Humanities 23:109-150. [link]

Steele TE, A Mackay, J Orton and S Schwortz. 2012. Varsche Rivier 003, a new Middle Stone Age site in southern Namaqualand, South Africa. South African Archaeological Bulletin 67:108-119. [link]

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