Kerry Greenwood: Tamam Shud

Then again, suggested my learned friend and a senior scientist Vanessa Craigie – I have been boring my friends to death about Somerton Man for months – what about blue-ringed octopus or snake venom? Death, in fact, by natural causes?

What an interesting idea. Dad was always going on about Adelaide snakes and I unashamedly sponged on her for introductions. And got Nick Clemman, a senior scientist at The Threatened Fauna Project at the Department of Sustainability and Environment and author of A Field Guide to Reptiles and Frogs of … Practically Everywhere. He has never met a scaly person he didn’t like.

After outlining the problem and reading the documents, Nick said:

It is certainly plausible that a human-delivered puncture wound from a syringe/needle would remain undetected either amongst ‘abrasions’, or actually be the source of a ‘boil scar’ (especially if it was relatively fresh). Similarly, it is plausible that he may have accidentally put his hand down on a snake, or even attempted to catch or handle a snake he encountered (not recommended but people do such things). A ‘hot day and warm night’ are precisely the conditions under which usually diurnal snakes become nocturnal. They have poor eyesight, and rely largely on chemoreception (a bit like an advanced ‘super’ sense of smell), and are thus unfazed by darkness, instead using their flickering tongue to ‘see’ at night. Although most folks assume that reptiles love hot weather, and think that the hotter it is the more likely it is that they are active, high temperatures rapidly kill reptiles, and on very hot days they will seek cooler shelters during the heat of the day, and become crepuscular or nocturnal.

So, even if not especially likely, it is not impossible that this person was strolling along the beach, went to sit, and put his hand on a snake. Only a year or two back a friend of mine who works for the council showed me pictures of a large Tiger Snake that was on the sand on St Kilda Beach; a relevant example of snakes occurring on an actual beach (not just in the dunes), and in a very urbanised area. Also, beach-washed, venomous sea snakes also turn up from time to time on the beaches of southern Australia.

The time of year is certainly spot-on for snakebite risk; the start of summer is a time when many snakes are very active. If the victim was fully clothed and wearing long trousers, this lessens the likelihood of snake envenomation after inadvertently stepping on a snake. I mention this because snakes are often active after dark on hot days/nights, and are easily stepped on in the dark, but as local elapid (or front fanged venomous) snakes have very short fangs, long trousers afford some protection from bites to the lower legs. It is not out of the question that fangs would effectively penetrate light trousers, but it does lessen the odds. Of course, it remains plausible that he may have been bitten elsewhere on the body.

And generally on Adelaide snakes he had the following to say:

The Eastern Brown is not the only contender that naturally occurs in that general area. A close cousin, the clumsily named Strap-snouted Brown Snake ( Pseudonaja aspidorhyncha ), and the Tiger Snake ( Notechis scutatus ) are also possible, and both have the (proven) bioarsenal to rapidly kill humans. The near-beach habitat described sounds just fine for both species of Brown Snake, and for Tigers too. But both will also show up in areas with little or virtually no remnant ‘bush’.

Venom works differently to poison. It usually needs to be injected or absorbed, rather than ingested. Ingested venom (provided it is not absorbed through a mouth wound) would likely be rapidly and effectively neutralised by saliva. Still, I can’t see it becoming a popular condiment…

Re venom inhaled via cigarette or the like, I’m not 100 per cent sure, but my best guess is that it would not be fatal (again, it needs to enter the lymphatic or circulatory system to do its job as evolution intended). However, I am intrigued by what, if any, effects smoked venom would produce!

It is well within the bounds of possibility that any minor local/visible effects of envenomation could be overlooked post-mortem, especially back then, especially if there were other marks to ‘camouflage’ localised effects, especially if the victim was quite hairy, especially if the examiner suspected other causes, or was hurried, etcetera. As discussed, bites like this from some elapid snakes can leave little or no trace at the site of the bite, even when the bite proves fatal. The neurotoxins common in elapid venom can cause rapid death by asphyxiation via, in layman’s terms, preventing the brain’s signals from telling the diaphragm to breathe. It is a (very) long shot, but it would be possible to use snake venom to murder someone (milked venom delivered via a hyperdermic needle, or something like that), but that seems quite ‘hollywood’ to me…

Yeah, I still prefer the snake idea – sounds more likely than the octopus, even though it certainly would occur in the area. And a snakebite mark is almost invisible. No local rash or swelling, so don’t give up on the bite idea. Not impossible for someone who had a captive snake to bring it into contact with the victim.

My friend, Vanessa Craigie also had a suggestion to make:

I thought about blue-ringed octopus, which also causes death from motor paralysis and respiratory arrest within minutes of exposure, leading to cardiac arrest due to a lack of oxygen. They deliver venom by a bite from a horny beak, but given it’s such a tiny beast, such a bite probably wouldn’t leave much of a wound. They tend to live in crevices, but another Adelaide colleague says she’s seen them in a can on the beach. My problem with this one is again, what was the beach like – that is, were there any rockpools or beach rocks? Any sign that the victim had been in the water, even wading? On the downside, symptoms can include fixed, dilated pupils and nausea, so I’m not so keen on this one as an undetectable killer.

Nick added to this information:

Snakes in the Pseudonaja (Brown Snake) genus kill more people in Australia than other species, due to a combination of factors including: highly toxic venom that works especially well on mammals (like you and me), being common and abundant in disturbed areas where there are lots of people, and being more aggressive and inclined to bite than other species (as opposed to just bluffing, which many other snakes do, and humans frequently misinterpret as an attack).

Nick Clemman put me onto an even more eminent colleague, Dr Ken Winkel, the Director of the Australian Venom Research Unit at University of Melbourne, who was kind enough to read the autopsy results. He, unfortunately, could not advise me further. Though he could not have been more kind.

As to this mystery case, it certainly is that. I am not immediately struck by the possibilities of venom [no evidence of asphyxial mode of death, for example, whereas venom-induced paralysis is a very common mechanism of death after snakebite, especially in highly toxic elapids such as we have here in Australia, that is, things like death adders]. Ingested venom is not toxic so it would have to be injected. Many snake venoms cause inflammation and even tissue death at the site of injection, for example rattlesnake, vipers and many cobras, and this is associated with regional lymphadenopathy making their injection site somewhat conspicious – no evidence of that here as I understand it.

Snake venom often causes nausea and vomiting. So again no sign of that here as his pastie was still intact. Dr Winkel went on to explain further:

Also, as far as I can see digitalis [a heart stimulant derived from foxgloves] has been repeatedly suggested. This can be ingested and rapidly lethal. The pity is that this could have been confirmed today if they had kept tissue (especially blood) samples. The first thing I would look into is bone mineral analysis that should reveal where this person lived and something of their diet and habits in life. I would not think formaldehye would affect that kind of analysis – but I am not a forensic scientist.