A Shell That Is But A Shell Of Its Former Self

I'm shocked, shocked to find that mythopoeic archaeology is going on in Italy! [Apologies to Captain Renault.]

Location of Fumane Cave and two palaeontological localities mentioned in Peresani et al.

Once again, the credulous, but impartial, referees at PLoS ONE have ensured that no matter how far-fetched the inference, they're dedicated to giving it an outlet. [I'd really like to know their rejection rate. Any ideas? I kinda doubt there is one! But, that's beside the point. Because that would be argumentum ad hominem, and everybody knows that's not a valid argument!] 

Peresani M, Vanhaeren M, Quaggiotto E, Queffelec A, d’Errico F (2013) "An Ochered Fossil Marine Shell From the Mousterian of Fumane Cave, Italy." PLoS ONE 8(7): e68572. doi:10.1371/journal.pone.0068572

In this paper the authors analyze the bejeebuz out of a single, fragmentary specimen of Aspa marginata found in a Mousterian stratum. They say that the only possible conclusion is that this relatively tiny fragment of a marine shell was brought to the cave by [style-conscious] Neanderthals, [inexplicably] rubbed to create minute striations on the interior, and then smeared with hematite [to produce a nice, red lump that was somehow then displayed as a fashion statement]. These are the crucial inferences on which they base their claims.

1) The specimen is a fossil of Aspa marginata.
2) The specimen must have originated in fossiliferous rock 100 km away.
3) The specimen was originally 34 mm long and 24 mm wide.
4) The specimen has numerous minute striations on the inner lip.
5) The specimen has some hematite in numerous little surface dents.

Unfortunately for their argument, the authors have violated Rule #1—they haven't considered all of the natural processes that could account for a) the presence of a single small fragment of non-local shell, b) the striations on the lip, and c) the presence of hematite on the shell.

I want to apologize in advance for the length of this blurt, and for the length of time it has taken me to squeeze it out. It takes a long time to argue against the claims made in a paper like this, if only because the claims are based on limited 'evidence' and not much else. I've made an effort to perform the due diligence that the authors should have taken on. If they'd made the same effort as me, they would never have submitted their findings to a reputable refereed journal, much less to PLoS ONE!
[Because this blurt is so long, I'm going to make the better part of it accessible "after the fold," as they say in blogistan. That means, simply, that the article is continued on a secondary web page.]

Let's take the inferences one at a time...

Inference 1: Taxonomic identification

I have no quarrel with their species ascription. After all, I'm not a malacologist, nor an invertebrate palaeontologist. Despite my shortcomings there does seem to be some dispute in the literature as to the correct genus name—both Bufonaria marginata and Aspa marginata are used as is Bursa marginata [although, apparently, Aspa now has the edge over Bufonaria and Bursa].

Inference 2: The shell's provenance [or, to be more correct, provenience]

A. marginata has occupied the seas of Italy's part of the world since at least the Miocene [when, in fact, the Mediterranean was created by the collision of the African and Eurasian tectonic plates]. It's true that A. marginata occurs in fossiliferous sediments within 100 km or so of Fumane Cave, as the authors tell us. They're also careful to point out that in the present day the species doesn't occur the Mediterranean basin. Doesn't it seem a little odd that they've gone to the trouble of researching the present-day geographic distribution of A. marginata when they're dealing with a 47,000 year old discovery? Well, even if it doesn't seem odd to you, it does to me. I suppose it's possible that the authors wanted to rule out any possibility that their specimen was picked up on the Mediterranean littoral 47 ka. But why? For us to accept such a statement we'd have to think that marine conditions and A. marginata's trophic preferences have been static for those 47 ka. So, as my dear, dead Dad used to say: Beats the shit outa me. Furthermore, I'm surprised that they would cite the World Register of Marine Species as the source for their claim, because it seems to contradict their claim. I went to the same source and found two citations that list the Mediterranean as one of the places that this species lurks—here and here. As Frodo would say, I'm confusticated and bebothered.

If you look at Peresani et al.'s figure below, you may notice a very polished sheen on the archaeological specimen's inner surface, which I've circled in red. [Since we're given four views of the Fumane Cave specimen, the arrows are there to help you by pointing out the corresponding anatomical points on the archaeological and the comparative specimens.] I'll defer to the invertebrate palaeontologists in the group if I'm wrong. However, I think the lustre of this specimen's columella means that there has been no or very little mineralization of this specimen. In other words it appears to be an unaltered fossil, to use palaeo-speak. Such 'fossils' are a frequent occurrence in certain lithofacies. I'm also very curious as to how you would tell an 'unaltered' fossil from a contemporary one. *sigh* The lyf so short, the craft so longe to lerne.

a = archaeological specimen; b through d = comparative fossils

Unfortunately, we don't get to see inside the three comparative specimens. So, the sceptical among us are left to depend on the authors' 'authority' in this matter. And you and I know that argument from authority is not a valid form of argument.

In reality it's of little consequence whether or not the Fumane Cave specimen is truly a fossil or was a living organism at the time of the Neanderthals. There are any number of ways that a cm-sized clast of any solid could have arrived in the cave unintentionally, whether or not it was a fossil that had eroded out of bedrock. Any furry or hairy creature can transport small bits in matted hair for great distances. Had one such animal been killed or scavenged by a Neanderthal, a small fragment of shell could easily have come to rest in the cave and be preserved. The same would be true of other predators that transport carcass parts away from a death site, such as wolves and hyaenas. In this case, the authors' claim is just one of a number of possible scenarios. And a not very important one, at that.

Inference 3: Estimating the original size

I honestly don't have a clue why the authors thought it important to estimate the specimen's original size, nor do they offer a reason. Nevertheless, they take great care to justify their estimate of the original dimensions—including publishing a half-page regression curve to illustrate their six data points, seen below, and a column-width table containing the same six measurements. I feel so inadequate that I don't see the point. It's a mystery to me why the referees didn't just tell them to axe this part of their paper. I realize that in this digital age, bits and bytes are cheap, and the page count means little compared with the days of print-only publication. However, it's still true that you and I have precious little time to read unnecessary verbiage. Under the circumstances, absent a compelling explanation, I have to conclude that their treatment of the specimen's original size is a total waste of my time.

A bit of errant pedantry—Height is not spelled Heigth in any dictionary I've poked my head into. I guess proofreading is the first casualty in an electronic journal that promises "fast publication times." 

So, having thus demonstrated that they are the best darned fossil-shell, original-size estimators this side of the Pecos River, the authors get into the real purpose of their paper.

And I'll see you after the fold!

Ceci N'est Pas Une Barre de Savon: Apologies to René Magritte

Ceci n'est pas une barre de savon 

Behold the lowly bar of soap [albeit somewhat used]. In the past I've used similar objects to make fun of handaxes [here and here]. Although the tone of those essays was tongue-in-cheek, my purpose was serious: a used bar of soap is an excellent analogy to use when theorizing about the lithic reduction sequences that result in what's come to be known as 'the' Acheulean handaxe, and what's called the 'Levallois technique,' the two main aspects of which are the 'Levallois core' and the 'Levallois flake.'
     Some of you may lack an intimate knowledge of Middle Palaeolithic stone artifacts and the history of their interpretation. I must warn you. What I'm about to say will not be well received by Very Serious [Palaeolithic] Archaeologists. These objects have been heavily theorized, going back more than a century, and their 'reality' is a foregone conclusion in the disciplinary 'culture.' As such, my efforts are akin to pissing into the wind.

Me and my Level 4 Biohazard suit 

Never mind about that. Somebody's gotta do it. Might as well be me. Besides, I've taken a face-full so many times I'm ready for anything in my Level-4 Biohazard suit! Regardless, it does get tedious donning and doffing these togs every other day or so. [And guess what? They don't protect against hurt feelings or embarrassment. So, they're not perfect, 'specially when you consider the atmosphere of acrimony that sometimes prevails in  this binness.]
     Back to the matters at hand. By now you may have consulted my previous two outings on this issue. Today I'm hoping to break the argument down into its components so as to make a step-by-step case as to why a used bar of soap is a good analogy for the handaxe and the two genres of Levallois artifacts.
     First of all, let's talk about the functional underpinnings, beginning with a question [and don't get all bent outa shape. This isn't a 'Why did the chicken cross the road' joke!].
     "Why did the bipedal ape bang one piece of rock against another piece of rock with the result that a small, sharp-edged fragment was subtracted from the larger of the two blocks?" Was it to make the large block smaller? Not likely. Was it to prepare the large block for the removal of a second or third sharp-edged fragment? Hmmm. Let's think about that for a moment. It seems rather unlikely, given that this was just about the first time a bipedal ape left such a trace in the palaeontological record.
     Remember that we don't know much about the cognitive abilities of those first 'flintknappers.' All we can say for certain is that they would have been every bit as smart as the last common ancestor that we humans share with chimps. Best guess? A chimp-like brain. So, the cognitive abilities of those first 'flintknappers' were at best equivalent to those of present-day chimpanzees [unless we're to imagine that today's chimps have de-volved from a golden age of chimp cognition, which seems, again, unlikely].
     Do we think that the first 'flintknapper' banged one rock against another because it envisioned a useful sharp bit in the block of raw material and then struggled to work out a way to get it out? I'm gonna say that's also highly unlikely. [By so saying I might be accused of a certain bias against our early progenitors. However, I think it'd take one gigantic heap of special pleading to suggest that the first 'flake' was the result of forethought.] So, if not because of forethought, how do we explain that first act of rock against rock, and the removal of a sharp fragment. Here I'm jumping into the realm of speculation.
     I see a couple of possibilities. First, it could have been accidental, the result of a meaningless, nothing-better-to-do-at-the-moment banging together of two rocks with the unexpected effect that a small, sharp-edged fragment was detached from one of the two rocks. Second, it may have been a cognitive leap based on observation. In this scenario the first flake removal was an effort to replicate the result of two pieces of rock, in nature,  coming into contact with violent force such that a small, sharp fragment was detached. Not much to choose between there. Could go either way. What about that second possibility? How could that have occurred?
     I see at least a couple of ways that our bipedal hominid might have espied pieces of rock coming into contact in such a way that that first 'flintknapper' decided to take a *cough* crack at it. The first possibility is that it was, once again, a natural occurrence. Picture a cliff face from which, at random, fragments are naturally detached and fall to ground level with great force. At some point one block is going to come crashing down on another one resting on the surface and voila! The flake is born. The other possibility is that our incipient 'flintknapper' was out foraging one day with a fist-sized rock that was intended to be used as a missile in case it was surprised by a vicious predator [or to scatter a bunch of scavengers, or something equally as efficacious, in the palaeolithic sense]. Fast forward to the confrontation. Bipedal hominid flings rock at lion and misses, hitting cliff face or rock outcrop. Lion runs off. Our intrepid hominid goes to retrieve missile. It looks different now. There's a chunk missing. Hominid glances at ground. Spies flake. Picks up flake. 'Refits' flake. [Please, please, don't somebody use this scenario to argue for the presence of lithic analysts at 2.6 Ma!] Our better-than-chimp-brained bipedal ape puts two and two together and hominids lived happily ever after...
     So, our choices are 1) meaningless rock banging leads to lithic technology, or 2) observation of the results of rock banging leads to lithic technology. I think 2) is most likely. As for the event that brought about the observation, the possibilities are 1) naturally occurring fracturing, or 2) a rock used as a missile fractures when it impacts a larger rock mass. I think we must begin from this supposition, that our 'flintknapper' observed a natural phenomenon and put two and two together. This is the explanation that requires the least speculation. But, of course, it doesn't rule out the missile scenario.

     Just an aside, here. How did our savvy, soon-to-be 'flintknapper' know that a sharp rock could function as a cutting or scraping tool [which seems the most logical function for the arch flake and its progeny]? I reckon it's a no brainer. [Well, okay, it's a chimp brainer!] Ever bang your head on a sharp overhanging object, whether rock or other material? Hurts. There might be blood. Same with walking barefoot on sharp rocks. It probably didn't take an Oldowan Einstein to see the utility of sharp-edged rock fragments. So, it seems most likely that the first sharp stone flake removed intentionally from a block of raw material was used to cut or scrape something that couldn't be cut or scraped using fingernails or teeth. [It matters little to this discussion which of those two activities was primary in hominid evolution.] What matters is the result: one sharp fragment and one block of raw material from which it was removed.

     By now you're prolly wondering what any of this has to do with soap. I'm getting there. Be patient.
     If the entire archaeological record consisted of a sharp-edged fragment of rock--i.e. a flake--and the lump of raw material from which it was detached--i.e. a core--do you think archaeologists should ignore the flake and try to figger out what the lump might have been used for? Would that same archaeologist look at a used bar of soap and ignore the material that had been removed to wash somebody's hands? They might if they had no idea that any material had been removed in its creation. So, under such circumstances we could forgive the soap analysts if they focussed on the bar and not the lather, and dubbed the used bar a work of art or, well you can see what I'm up to. In the next chapter I'm going to argue that this is just what the earliest palaeolithic archaeologists did, and for much the same reason--at the very beginning the flakes--the lather, if you will, of a lump of rock--were very likely not in the picture.
     For now, I'll just foreshadow that next installment with an example from recent palaeoanthropology. Have a look at the illustration below. These are some of the oldest stone artifacts, from Kada Gona, Ethiopia, at around 2.65 Ma. These were reported in a 2000 Journal of Archaeological Science publication by Sileshi Semaw, "The World’s Oldest Stone Artefacts from Gona, Ethiopia: Their Implications for Understanding Stone Technology and Patterns of Human Evolution Between 2·6–1·5 Million Years Ago." The typological paradigm that's in play in these descriptions is a direct descendent of the first discoveries of Pleistocene stone artifacts in Europe, including those that were described from the very beginning as hand axes. The Kada Gona archaeologists are obviously reluctant to suggest that any of the objects shown are handaxes (although number 2 would be a good candidate for what the Qesem Cave and Kathu Pan 1 teams have described as a "handaxe roughout"--a pre-form, in other words). How number 2 escaped such a claim, and indeed, how the Kada Gona archaeologist missed his chance at claiming the earliest handaxe, is beyond the ability of this little brain of mine to understand. Unless, of course, said archaeologist had been brought up to think that handaxes weren't even invented until the Acheulean stone industry appeared, at about 1.5 Ma.

As you can see in the caption above, the archaeologist makes every effort to downplay the flakes, and to ascribe a meaningful function to the lumps from which the flakes were removed. Number 1 is a "unifacial chopper," while number 2 is inscrutably identified as a "discoid." Number 3 isn't just another unifacial chopper, it's a unifacial side chopper. [Explain that one!] Number 4 is a unifacial end chopper. Doesn't it look like 1 and 3? It does to me. But, then again, I'm not a lithic analyst. The fifth is a 'partial' discoid, presumably because it's not really discoidal at all. So it's an irregular discoid! Criminy! 6 and 7 are called the same thing as 3. UNBELIEVABLE! It's the flake, Stupid! [Recalling the Clinton campaign strategy: "It's the economy, Stupid!"] These so-called choppers prolly couldn't chop a pound of butter without smearing it all over Olduvai! Choppers, my ass. Are we to believe that these Ur-flintknappers, who had just learned to walk for gawd's sake, could possibly conceive of a chopper, or an axe? Good luck with that one.
     On the basis of the foregoing evidence courtesy of the Kada Gona archaeologist, I'm gonna guess that any lumps of stone with fewer than a half-dozen flake removals were simply not considered worthy of discussion [much less illustration in an august refereed journal]. But you and I know that they're there in the assemblage, disguised as 'mere' cores, and giving lie to this preposterous labelling of more heavily used lumps as 'choppers' and 'discoids.' What a load of crap. And I'm talkin' poop of pachydermical proportions.

I'm outa here.

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