About those Neanderthal eagle talon ornaments

The recent paper by Morin and Laroulandie (2012) in PLoS ONE has been creating a bit of a buzz, suggesting as it does 'non-nutritional' and possibly symbolic use of eagle talons at two Mousterian sites in France. The authors rightly emphasize that the discovery of several eagle talons bearing cut marks from La Ferrassie and Les Fieux articulates quite well with the evidence from Fumane that Neanderthals purposefully harvested visually striking feathers from a variety of bird species, especially raptors. Hawks underscores their observation that this behavior at La Ferrassie likely goes back almost to 100kya, pushing back the age for potentially symbolic use of bird parts by Neanderthals considerably. In my mind, the study also shows how productive it can be to take a new look at old collections.

While I think the paper reports some very interesting observations and that it makes a solid case overall, I'm left wondering about two things:

1) How were these things used as ornaments? They're not pierced, nor do they display no obvious wear traces from having been worn suspended on strings or thongs. With purported feathers, it's one thing. But these things puzzle me a bit from that standpoint, since even the shells found in Aterian and other MSA sites show some kind of wear from having been strung and worn. 

2) I would have loved to see better shots of the cut marks. By this, I mean microscopic shots of the internal morphology of some of these marks themselves to show unambiguously that they were made by stone tools? Don't get me wrong, they certainly look like cutmarks, at least superficially, and their standardized placement on multiple specimens strongly supports the authors' claim. But as the controversy over the Dikika cutmarks has shown all too well, multiple factors can result in marks that can look like those produced by stone tools, so why not rule it out with some good photographs in this case?

Be it as it may, these new data build on the growing corpus of evidence for the use of things like feathers, ochre, manganese and shells as ornaments by Neanderthals well before the arrival of modern humans on the scene. All in all, it also suggests that different groups of Neanderthals likely used different types of ornaments and coloring materials depending on the ecological setting and available animal and mineral resources.

Reference:

Morin E , Laroulandie V (2012) Presumed Symbolic Use of Diurnal Raptors by Neanderthals. PLoS ONE 7(3): e32856. doi:10.1371/journal.pone.0032856

Shake your (Acheulean) money maker

There was a paper presented by Mimi Lam at the last AAAS meeting in Vancouver and which was covered in LiveScience last week and has bit causing something of a stir (and it spells Acheulean correctly!). While I'm always leery of relying only on press reports to make sense of unpublished papers, its abstract is available online and provides a bit more info. In a nutshell, one the arguments of the paper is that by the Middle Pleistocene, handaxes might have been used as a form of currency. I've talked about handaxes before on this blog, along with some of the debates about what drives their morphology - the focus is often on their alleged symmetry and the fact that this feature might not have been purely functional.

I wasn't at the AAAS meetings, so I didn't hear the paper. All I've read so far are the LiveScience piece, the abstract, and a very thoughtful blog post by Rosemary Joyce in which she rightly points to the at the tangled ball of conceptual yarn that money or currency represents from an anthropological standpoint. Definitely worth a thorough read.

My main concern about the study, however, has to do with the handaxes themselves. There is this notion (often repeated in archaeology textbooks) that they can be very symmetrical, and that the overall degree of symmetry in handaxes increases over time. Frankly,  I don't think we can safely assert this at all. Sure, handaxes can be symmetrical on occasion, no question there. But to my knowledge, this remains a very qualitative impression based on selected samples of handaxes, with selection operating both on the geography and age of the biface samples being observed, as well as on the fact that these samples themselves can be selected for. By this, I mean what gets considered a handaxe/biface and considered in these studies about their symmetry (and what the controls are to evaluate what is 'unnatural' symmetry in various contexts), and how that can vary across analysts and studies.

The main problem with the 'time-vectored increase in handaxe symmetry' as I see it is this: to the best of my knowledge, this hasn't been demonstrated empirically to hold true across all of the Old World. Yes, this seems like a fairly tall order. But this is the scale that is implied by this view. Based on my own biased view and experience with handaxes (and I've looked at a few), the opposite could even be said: there is no fundamental change in the degree of symmetry in handaxe assemblages over time - symmetry is a contingent variable determined by factors like blank size and shape, reduction intensity, use-life, technical skill, and maybe social considerations - the social dimensions being the hardest of all to establish objectively, let along attribute a function to. So, if this idea is not demonstrated, any interpretation of handaxe function based on symmetry is also potentially problematic.

I was talking about this with a colleague on Friday, and it struck us that a great dissertation idea would be to actually test this. What you'd need is a large-ish area with many handaxe assemblages recovered using modern excavation techniques for which a baseline chronology is known - some place like the Middle Awash River Basin, maybe. Then, you explicitly define what gets considered a handaxe, and you apply it to all these assemblages (e.g., at minimum, any piece with removals from both surfaces - this is obviously a minimalist definition, but it's given here as an example). Then, you define a way to measure symmetry and establish a baseline for what is considered 'symmetrical' or whether you're looking at symmetry as a continuous variable (ideally, you do both in order to fend off eventual critiques). Then, you get a sense of raw material constraints, site function and reduction intensity for each assemblage, in order to see whether or not any of these is a recurrent conditioner of handaxe morphology, and to factor them out if they do. In particular, you need some controls such as an evaluation of how inherently 'symmetrical' cobbles or flakes used to make handaxes are at various locales, and whether or not this is correlated to symmetry in various assemblages across the study area. Lastly, you measure symmetry on these handaxe assemblages and then, you look at trends over time. Then, you look at various measures: mean vs. median symmetry, coefficient of variation, spread of values, whether or not certain levels of symmetry are only reached after some point in time; the list goes on and on. The point is, we need to actually demonstrate this at the very least at a regional level before we can even consider taking 'increased handaxe symmetry' as the starting point for any subsequent analysis. So there - if you're a graduate student looking for a project, feel free to take this one. I can all but guarantee you that the resulting papers, whether they demonstrated one or the other conclusion, would become ridiculously highly cited.

I think that what we now know about technology (especially earlier technologies like the the Oldowan) would set the null hypothesis here as being that we shouldn't expect increasing symmetry or standardization over time. In other words, high degrees of symmetry can be present from the beginning of the Acheulean and low symmetry can occur in its latest phases. If you look at the Oldowan, the data clearly indicate that people didn't start by knocking off one flake, then a few thousand years realizing that they could knock off another one, and then another one yet more thousand years later. Quite the opposite, it seems that by the time people start regularly working stone, they get it pretty well: they know how to knock off flakes in succession, they realize that different materials flake better than other, going to some effort to get the better stuff (e.g., Stout et al. 2010). My impression is that the same is likely to be applicable to handaxe technology: once people start flaking cobbles bifacially, they also get it: they realize that you can knock flakes off both surfaces, often using one removal as the starting point for removing another one. And if they understand this, then making an object symmetrical as a result is also implicit - the question becomes why symmetry in certain case and not in others, and why this is the case

So, to go back to Lam's argument, my take on it is not so much that it's wrong (it might end up being right) that I think that we don't have nearly the archaeological resolution we need to objectively discuss the issues she tackles, especially those linked to the question of increasing handaxe symmetry over time, let alone the interpretation of such a pattern. Only when the baseline archaeological work has been conducted, can we really hope to usefully revisit the question.

Some earlier posts on the Acheulean and handaxes:


Plus-sized in the Pleistocene

Two sides to every biface

I say Acheulean, you say Acheulian


References and some suggested reading:

Machin, A. 2009. The role of the individual agent in Acheulean biface variability: A multi-factorial model. Journal of Social Archaeology 9: 35-58.

McPherron, S.P. 2000. Handaxes as a Measure of the Mental Capabilities of Early Hominids. Journal of Archaeological Science 27:655-663.

Monnier, G. 2006. The Lower/Middle Paleolithic Periodization in Western Europe: An Evaluation. Current Anthropology 47:709-744.

Nowell, A., and M.L. Chang. 2009. The Case Against Sexual Selection as an Explanation of Handaxe Morphology. PaleoAnthropology 2009: 77-88.

Stout, D., S. Semaw, M.J. Rogers, and D. Cauche. 2010. Technological variation in the earliest Oldowan from Gona, Afar, Ethiopia. Journal of Human Evolution 58: 474-491.

Bitumen used as hafting material in the Middle Paleolithic of Romania

Cârciumaru and colleagues (2012) report on artifacts from Gura Cheii-Râşnov Cave (Romania), of which a couple bear residues of a blackish material on their surfaces. One comes from the one of the site's Upper Paleolithic levels, while the other comes from its Mousterian deposit which date to between roughly 33.3-28.9 kya (uncalibrated radiocarbon ages).

The reason this is noteworthy is that the authors identify the black residue sticking to the surface of these tools as bitumen (albeit heavily weathered), which they interpret as evidence for those tools having been hafted. This is not a first. The use of bitumen as hafting material in the Middle Paleolithic is known from the Levant, at the site of Umm el Tlel, in levels ranging from 40-70kya in age (Boëda et al. 2008). What is significant, however, is that these new data from Gura Cheii-Râşnov Cave provide the first evidence of using bitumen as a hafting material in the European Middle Paleolithic. From a behavioral standpoint, this joins the evidence for birch pitch tar documented at several Middle Paleolithic sites as old as 125ky bp in Germany (see Pawlik and Thissen 2011) and maybe even older in Italy (Mazza et al. 2006) as evidence for hafting material. This is significant because it reflects the Neanderthal capacity to come up with different solutions for the same problem, namely finding an adhesive to help in crafting composite weapons. In areas where bitumen sources were present and accessible, it makes sense that Middle Paleolithic hominins would not have bothered to go through the time-consuming process of birch pitch tar production detailed by Pawlik and Thissen (2011) when they needed an adhesive and a naturally occurring one was readily available.

Another interesting dimension of the study by Cârciumaru et al. (2012) is that it tells us something about the potential geographical range of the site's occupants. While the precise location where the bitumen was procured remains an open question, the authors indicate that there are deposits of bituminous limestone located about 20km away from the site, and that these deposits were definitely used by the Gravettian occupants of the site who procured high-quality flint from the region where they are found. Alternatively, the also mention a source of bitumen located about 100km to the south of the site. While a local procurement of any material can reasonably be argued to be the null hypothesis of any behavioral interpretation for the Paleolithic, should additional information eventually indicate that the more distant source was used, it would make this the longest distance over which bitumen was procured in the Middle Paleolithic, since the bitumen found at Umm el Tlel came from a source 40km distant from that site (Boëda et al. 2008). Additionally, as mentioned in other posts, Neanderthals are known to have procured lithic material over much longer distances than that, so it wouldn't really be all that surprising if they also collected bitumen from distant sources - especially considering that unlike stone, bitumen doesn't break irreparably and can be re-used and re-shaped over time, which makes its overall utility and use-life much greater than that of stone, thus perhaps justifying traveling long distances to procure it.

References

Boëda, E., Bonilauri, S., Connan, J., Jarvie, D., Mercier, N., Tobey, M., Valladas, H., al Sakhel, H., Muhesen, S. 2008. Middle Palaeolithic bitumen use at Umm el Tlel around 70 000 BP. Antiquity 82: 853-86.

Cârciumaru, M., Ion, R.-M., Niţu, E.-C., Ştefănescu, R. 2012. New evidence of adhesive as hafting material on Middle and Upper Palaeolithic artefacts from Gura Cheii-Râşnov Cave (Romania). Journal of Archaeological Science, doi: 10.1016/j.jas.2012.02.016

Mazza, P. P. A., Martini, F., Sala, B., Magi, M., Colombini, M., P., Giachi, G., Landucci, F., Lemorini, C., Modugno, F., Ribechini, E. 2006. A new Palaeolithic discovery: tar-hafted stone tools in a European Mid-Pleistocene bone-bearing bed. Journal of Archaeological Science 33: 1310-1318.

Pawlik, A., Thissen, J. 2011. Hafted armatures and multi-component tool design at the Micoquian site of Inden-Altdorf, Germany. Journal of Archaeological Science 38:1699-1708.