The Nataruk massacre, about 10,000 BP

[Jim Webster]

I've seen it done. Drop something into mud covered by shallow water and it can very quickly sink out of sight
Never timed it with relation to crocodiles but seen a Border Collie drop a dead lamb and challenged and minutes later she struggled to find it 

[Sharur]

Thanks, Alastair; I am impressed by sediment that can settle over/deposit upon bodies more rapidly than vultures can gather and drop from the heavens or crocodiles turn up for lunch.  We can give it the benefit of the doubt, although I would expect a lot more bodies of various creatures of all sorts to be preserved this way if this is indeed what happened.

It's the actual mechanism of deposit and weight of the object that are key here Patrick. Dropping something into the water so it hits the muddy bed firmly stirs up so much fine sediment so fast, the water becomes too murky to see anything in - predators won't waste time hunting for something they can't detect (in-line with Jim's lamb comment, of course). The sediment then settles out at variable rates, keeping the water murky while the bodies get quickly covered. By the time it's cleared enough, there's nothing left to see. Or if there is, it gets eaten preferentially - some of the bodies in this case were incomplete. Plus a group of violent humans cavorting in triumph on the bank and in the shallows nearby will deter (or indeed kill) pretty much every potential animal predator.

An animal that dies in the water will be either eaten more or less immediately (because something attacked it for food), or if it simply died of a non-violent cause, it'll descend relatively slowly to the sediment, stirring little of it up, so will be found and eaten easily by carrion-hunters, etc. The fact the Nataruk people were probably killed violently beside or indeed just in the lagoon ironically makes their preservation this way more likely!

The palaeontological record has a lot of examples of preserved fossils whose survival seems to have proceeded by very similar mechanisms certainly, albeit of a more natural form, like underwater landslides.

[Patrick Waterson]

We are understandably assuming the humans, or rather some of the humans, were dropped into the sediment rather than the sediment being spread over the humans.  The latter would be a bit of a challenge: apparently Lake Turkana has a 'high' sedimentation rate of 1 metre per 1,000 years ...

There is still it seems to me, a problem (sorry to carry on about this, but it does look like a problem to me).

The challenge is to get the sediment to set rapidly, because otherwise no matter how well the body stirs it up and gets covered, decay will produce gases and what will shortly emerge from the sediment is what river police term a 'floater'.

In the ordinary course of events sediment will not, as far as I am aware, set with sufficient rapidity to hold bodies once the process of decay has produced sufficient gas buildup and hence lift to release the body from its temporary enclave.  Indeed, if it could set with such speed, it would be hard to see how it could remain sufficiently penetrable for any length of time to accept a body in the first place.   As I understand it, the sediment needs to be dried out swiftly - and, ideally, compacted at the same time - so that it sets before the body can escape with its new-found lift.  The usual prerequisite for this is that the sediment needs to be heated up rapidly and on a large scale.  Such a process would appear to be beyond the resources of the average tribal raider.

[Sharur]

We are understandably assuming the humans, or rather some of the humans, were dropped into the sediment rather than the sediment being spread over the humans.

From the postures, it's hard to see how else they could have ended up as they were found.

The latter would be a bit of a challenge: apparently Lake Turkana has a 'high' sedimentation rate of 1 metre per 1,000 years ...

Well, setting aside extrapolation problems, that's assuming the bodies were covered only by a slow, steady process of material falling out of the water column with no other influences, which seems very unlikely to have been what happened here, as Jim and I have commented previously.

The challenge is to get the sediment to set rapidly, because otherwise no matter how well the body stirs it up and gets covered, decay will produce gases and what will shortly emerge from the sediment is what river police term a 'floater'.

Why does the sediment have to set? To get the bodies to float, aside from a sufficient depth of water, which may not have existed here (the exact physical circumstances of the lagoon aren't well-established, but it seems to have been shallow), you'd need to know more about the exact water chemistry at the time, its temperature, the nature of any organisms present in the water nearby which could have been removing the soft tissues from the start, and the state of those soft tissues on the bodies after they'd been killed by various apparently warlike means (plus any other perimortem soft tissue injuries resulting from trying to escape their attackers). Internal decomposition gases could easily seep away gradually, or otherwise escape, without the kind of build-up that creates floaters if the soft tissues were sufficiently damaged by whatever mechanism before such critical levels of gas build-up could occur, for example. Cutting open the belly, even in a small way, could be sufficient.

Forensic science is well aware there are a great many variables involved in the behaviour of dead human remains in water, many of which are not fully understood, and some of which have received relatively little investigation. That dead bodies will float in water eventually because of decomposition-gas build-up is generally considered a reliable overall point, but it is equally clear this does not happen in every case.

There's an online version of parts of Haglund & Sorg's Advances in Forensic Taphonomy: Method, Theory, and Archaeological Perspectives (2001, CRC Press) available via Google Books, and as luck has it, the entirety of Chapter 10, "Human Remains in Water Environments", pp. 201-216, is freely available in the online version (you can't download it, however - well you can, but only as a £79.20 e-book!), which is worth reading in this respect. Book link, then scroll roughly 2/3 of the way down using the scroll bar to find it.

Given the sediment wasn't rock when the bones were discovered and removed recently, yet was apparently comparable all around the remains, again there's no good reason to invoke anything other than the kind of scenario already outlined - bodies fall into shallow water with force enough to stir up sufficient lying sediment to cover most of them fairly rapidly.

[Patrick Waterson]

Again, Alastair, very well-considered response.  Thank you.

The latter would be a bit of a challenge: apparently Lake Turkana has a 'high' sedimentation rate of 1 metre per 1,000 years ...

Well, setting aside extrapolation problems, that's assuming the bodies were covered only by a slow, steady process of material falling out of the water column with no other influences, which seems very unlikely to have been what happened here, as Jim and I have commented previously.

Precisely.  It is surprising how often slow, steady deposition is invoked when considering fossilisation, and how inadequate it is as a covering mechanism.  Covering has to be rapid, and relatively complete, which makes one wonder about fossil-bearing layers 50 feet deep elsewhere.  A curious point about the Turkana remains is the way articulated skeletons and fragmented skeletons are distributed without any apparent shallow water line.

The challenge is to get the sediment to set rapidly, because otherwise no matter how well the body stirs it up and gets covered, decay will produce gases and what will shortly emerge from the sediment is what river police term a 'floater'.

Why does the sediment have to set? To get the bodies to float, aside from a sufficient depth of water, which may not have existed here (the exact physical circumstances of the lagoon aren't well-established, but it seems to have been shallow), you'd need to know more about the exact water chemistry at the time, its temperature, the nature of any organisms present in the water nearby which could have been removing the soft tissues from the start, and the state of those soft tissues on the bodies after they'd been killed by various apparently warlike means (plus any other perimortem soft tissue injuries resulting from trying to escape their attackers). Internal decomposition gases could easily seep away gradually, or otherwise escape, without the kind of build-up that creates floaters if the soft tissues were sufficiently damaged by whatever mechanism before such critical levels of gas build-up could occur, for example. Cutting open the belly, even in a small way, could be sufficient.

The body I wonder about is the woman with crossed arms and legs bent to place the feet about the level of the hips, believed to have been a bound victim.  That skeleton was buried in sediment up to the neck with the head (and knees) missing.  One wonders that a scavenger would not have unearthed a body so shallowly-buried, especially as the head and knees would initially have been available as clues to the location once the smell of decomposition had drawn necrophages to the scene.  Yet the head and knees are gone as if removed with a bulldozer while the rest of the body, or at least skeleton, remains.  I would have thought that the sediment would need to change composition to something harder, or at any rate significantly drier and less permeable, to inflict so clear a demarcation line.

Given the sediment wasn't rock when the bones were discovered and removed recently, yet was apparently comparable all around the remains, again there's no good reason to invoke anything other than the kind of scenario already outlined - bodies fall into shallow water with force enough to stir up sufficient lying sediment to cover most of them fairly rapidly.

My question would be at what point the sediment changed from the original glutinous mess to the dry composition in which the remains were discovered.  Would not this have to happen quite fast in order to avoid mother nature's saprophytic servitors taking an interest, and for that matter to retain the corpses in any event, as decay and disarticulation would otherwise presumably follow their natural courses?

[Sharur]

It is surprising how often slow, steady deposition is invoked when considering fossilisation, and how inadequate it is as a covering mechanism.  Covering has to be rapid, and relatively complete, which makes one wonder about fossil-bearing layers 50 feet deep elsewhere.

Hmm. I suspect you're deriving your information from sources which are a little too simplified, Patrick. There are really many more factors involved in fossilisation than just rapid coverage after burial. Such things as the nature of the depositional environment, what has been preserved as a fossil by the time it can be recovered, the chemistries and physics involved in the burial mechanism, and a lot more besides, all need to be considered too. There's also the problem of "archaeological fossils" as opposed to "palaeontological fossils", by which latter I mean remains that have survived as rock - that is, where the original substance has been chemically replaced by rock minerals and/or where it survives as a physical cast in the surrounding material - as opposed to most archaeological examples, where the materials are frequently almost exactly what they were when they were buried (with caveats regarding decomposition, natures of the materials involved, environment of preservation, etc.). "Archaeological fossils" are essentially often those still at the start of the whole fossilisation process, geologically speaking. This can create problems for commentators who are asked to quickly and simply explain things - as is often the case online and in the popular media - because the possibilities for being misunderstood are huge.

Deep palaeontological fossil layers are scarcely problematic, but do need to be considered thoroughly. The timescales involved might range from comparable preservation mechanisms persisting for millennia (e.g. anaerobic deep water environments), to a massive landslide (or pyroclastic flow if we're thinking Pompeii) which last only seconds, for example.

A curious point about the Turkana remains is the way articulated skeletons and fragmented skeletons are distributed without any apparent shallow water line.

Not really. As noted at the start of the Supplementary Information PDF, the remains were already surfacing by deflation when first located, which would have at least partially removed the evidence for shore lines. That's one of the difficulties in pinning down more precisely the nature of the lagoon the bodies were preserved in.

The body I wonder about is the woman with crossed arms and legs bent to place the feet about the level of the hips, believed to have been a bound victim.  That skeleton was buried in sediment up to the neck with the head (and knees) missing.  One wonders that a scavenger would not have unearthed a body so shallowly-buried, especially as the head and knees would initially have been available as clues to the location once the smell of decomposition had drawn necrophages to the scene.  Yet the head and knees are gone as if removed with a bulldozer while the rest of the body, or at least skeleton, remains.  I would have thought that the sediment would need to change composition to something harder, or at any rate significantly drier and less permeable, to inflict so clear a demarcation line.

This is skeleton KNM-WT 71255, which appeared to have been a pregnant woman close to full term. I'm unclear though why you think she had been buried only partially at death. Her head and knees had begun to surface relatively modernly (i.e. long after the lagoon bed surface had been removed by wind erosion, but before she was discovered and excavated), and seemed to have been damaged over time because of that alone. Page 17 of the PDF, item 3.3.4, noted although her face had been exposed before recovery and broken away, fragments of her facial bones were found on the surface nearby, for instance.

My question would be at what point the sediment changed from the original glutinous mess to the dry composition in which the remains were discovered.  Would not this have to happen quite fast in order to avoid mother nature's saprophytic servitors taking an interest, and for that matter to retain the corpses in any event, as decay and disarticulation would otherwise presumably follow their natural courses?

Again, you're treating this too basically, Patrick. Part of the sediments higher in the sub-surface soil column would have remained partially liquified until there was no longer any water above them, and as the lagoon bed surfaced and "dried out" (in a loose sense, given soils retain a degree of water at varying depths below those uppermost layers exposed to the air anyway), the local vegetation would have taken over the "new" land and covered it over. We don't really know how deep the sediments would have been over the bodies by then, nor how long - decades to centuries, maybe - may have passed before the lagoon over the bodies dried up this way.

[Patrick Waterson]

"Archaeological fossils" are essentially often those still at the start of the whole fossilisation process, geologically speaking. This can create problems for commentators who are asked to quickly and simply explain things - as is often the case online and in the popular media - because the possibilities for being misunderstood are huge.

Dinosaur soft tissue preservation being a case in point ...

As noted at the start of the Supplementary Information PDF, the remains were already surfacing by deflation when first located, which would have at least partially removed the evidence for shore lines. That's one of the difficulties in pinning down more precisely the nature of the lagoon the bodies were preserved in.

This explains the misleading impression I had that KNM-WT 71255 had been only partially buried in sediment, having taken the article to indicate that what-you-see-is-what-they-had.  My thanks.

Again, you're treating this too basically, Patrick. Part of the sediments higher in the sub-surface soil column would have remained partially liquified until there was no longer any water above them, and as the lagoon bed surfaced and "dried out" (in a loose sense, given soils retain a degree of water at varying depths below those uppermost layers exposed to the air anyway), the local vegetation would have taken over the "new" land and covered it over. We don't really know how deep the sediments would have been over the bodies by then, nor how long - decades to centuries, maybe - may have passed before the lagoon over the bodies dried up this way.

And the roots of this local vegetation would not reach down and disarrange the skeletons?  They would presumably need to get down as far as standing water or at least moisture in the absence of a nearby and convenient lake.

It is also presumably considered that 'deflation' can be quite selective uncovering some bodies faster than others on account of local variation in wind patterns.  Maybe so.  Yet the fundamental question I still have is, if conditions were right for preservation on that particular occasion, why are we not finding more ex-lake shore skeletal remains in the vicinity?

The ubiquitous 'gravel with a patina' is also intriguing.  Any thoughts about that?

[Sharur]

And the roots of this local vegetation would not reach down and disarrange the skeletons?  They would presumably need to get down as far as standing water or at least moisture in the absence of a nearby and convenient lake.

This depends entirely on what the vegetation is. Not all plants have roots, many don't have roots that reach at all deep, while others simply don't need ground water. And we don't even know what the depth of the original sediment was when the lagoon ceased to be one.

It is also presumably considered that 'deflation' can be quite selective uncovering some bodies faster than others on account of local variation in wind patterns.  Maybe so.  Yet the fundamental question I still have is, if conditions were right for preservation on that particular occasion, why are we not finding more ex-lake shore skeletal remains in the vicinity?

All forms of wind erosion can have hugely variable effects, dependent on the nature of the wind and the eroding surfaces, including sub-surface aspects - the Aeolian processes Wikipedia page, for example, is brief but has some helpful introductory notes and images. The process is particularly complex, because it doesn't merely remove loose material, it also redeposits it elsewhere, and can simply move it from place to place, including back to where it started.

As for "today's" fundamental question (which doesn't seem to be quite the same as any you've asked previously ), well, take your pick, given the possibilities as to why something hasn't been found can be legion! Such as: There were no more bodies to be found; Preservation conditions were suitable only in this area; Other bodies may yet appear after further erosion and/or investigation; The attackers couldn't catch anyone else to kill...

The ubiquitous 'gravel with a patina' is also intriguing.  Any thoughts about that?

Wikipedia - Patina; And this would be relevant to your "fundamental question" because...?

[Patrick Waterson]

The ubiquitous 'gravel with a patina' is also intriguing.  Any thoughts about that?

Wikipedia - Patina; And this would be relevant to your "fundamental question" because...?

Because if we have significant ongoing wind erosion, what would it do to this patina?  For that matter, how is the sediment eroded while leaving the layer of gravel in place?  Or do I have the wrong end of the stick here?

As for "today's" fundamental question (which doesn't seem to be quite the same as any you've asked previously ), well, take your pick, given the possibilities as to why something hasn't been found can be legion! Such as: There were no more bodies to be found; Preservation conditions were suitable only in this area; Other bodies may yet appear after further erosion and/or investigation; The attackers couldn't catch anyone else to kill...

Sorry, I did not mean why do we not find more human bodies, but rather why no rich store of animal bodies in the same area?  I am mildly sceptical about a fossilisation 'window' whose duration matches the average visiting time of the Tardis.

Returning for the moment to the core of the topic, if we take this to be one of history (or prehistory)'s first preserved engagements, what can we tell about possible weapons and tactics?  Spears date back a long time (400,000 BC being the reckoned date for the first wooden shafts with fire-hardened ends) and bows to c.20,000 BC with slings possibly putting in an appearance around the same time or not long after (slings are not good at preservation so it is hard to tell).  Clubs and axes seem more nebulous, and it is a little early for swords.

Is anyone interested to try a weapons and tactics analysis from the skeletons?

[Patrick Waterson]

Just in case anyone is interested ...

"No cut-marks were observed among the skeletons from Nataruk, implying that the practice of dismemberment  and  trophy-taking  was  not  part  of  the  behavioural  repertoire  of  these foraging  communities.  The  lesions  among  the  people  from  Nataruk  are  indicative  of  trauma caused  by  projectiles –  supported  by  the  presence  of  the  actual  lithic  projectiles  in  two individuals and lesions to the neck and head consistent with sharp and non-sharp projectiles, by  sharp  force  trauma  to  the  face,  head  and  hand,  and  by  blunt  force  trauma  to  the  head, thorax  and  possibly  knees.  Fractures  on  the  hands  and  knees  were  observed  on  individuals who also had head (KNM-WT 71251, KNM-WT 71254), neck (KNM-WT 71 256) or thoracic injuries (KNM-WT 71259), and may be part of the single events." - Nature magazine 50-page pdf, page 11

So the learned scientists consider that projectile weapons only were used: melee as we understand it did not take place.  One may note the implication that a wide variety of sharp and blunt projectile weapons were used as opposed to the fairly homogenous one or the other (either slings or bows/javelins) that one might expect from a prepared war-party.

Then there is the distribution of injuries on individuals.  To keep this brief, I shall mention only two to begin with, but these should illustrate the problem.

KNM-WT  71251: an obsidian 'bladelet' scored the skull on one side, becoming embedded but not penetrating.  On the other side of the skull, something hit and penetrated with the force of an 8mm bullet ("The  perforation  has  a  circular  section,  missing  the  anterior  portion,  with  a maximum  diameter  of c. 0.8  cm.  The  external  margins  are  regular  and  sharp;  a  series  of associated  small  depressed  fractures  are  observed  on  the  posterior  margin  of  the  lesion. The direction of impact appears to have been from a posterior direction.").  In addition, both femurs were hit by something blunt with bone-cracking force, as were both tibia.

So how would this have worked?  Would there have been a slinger who showed off by hitting each major leg-bone in turn and then handed over to an archer who shot one obdisian flake-headed arrow so weakly that it could not scrape its way across the skull, and then another which was so powerful as to smash its way into the brain, and, unlike its counterpart, had a head of circular section?

KNM-WT  71253: blunt object cracks cranium (original wound lost but cracks exist in surviving material); sharp objects make holes in 3rd and 7th neck vertebrae but no weapon heads found therein.

Again, do we have a show-off archer who puts two rounds into the neck of a presumably moving target just to show how clever he is?  And what happened to the heads of his arrows?

Fire-hardened arrows would explain a lack of arrowhead debris within the vertebral lesions, if not why one was round-sectioned and the other diamond-sectioned.  Yet why would the missile-equipped raiders use obsidian-headed and fire-hardened arrows together?  Puzzling, at least to me.

[Dave Beatty]

Might I recommend a couple of books that relate? "Constant Battles by Steven LeBlanc and  "War Before Civilization, the Myth of the Peaceful Savage" by Lawrence H. Keeley both deal with the ancient problem of human warfare.

I'm strongly inclined to side with the archaeologists on this one - it is the earliest example of warfare to date.

[Dave Beatty]

And not quite so old, just 2000 years BP, from Utah 90 individuals killed in what has been called warfare between groups of Basketmaker people:

http://westerndigs.org/skeletons-in-utah-cave-are-victims-of-prehistoric-war-study-says/

Dave

[Patrick Waterson]

"While Geib and Hurst don't contest that the 90-some dead in Cave 7 were likely buried at more than one time, these results lead them to conclude that the site's most salient feature — the nearly five dozen brutalized bodies — were indeed the result of a single massacre."

And this seems a reasonable conclusion: the bodies constitute groupings from more than one time or occasion, but one particular grouping seems to have been deposited together, in a hurry and with combat-related injuries.

However they were buried in a cave, not in sediment next to a lake, so while this does indeed look like Basket People tribes doing unpleasantness unto each other, I am not sure it goes any way to explaining how the Nataruk victims came to meet their doom.