dimfuture.net

The Loch Ness Monster, considered as a previously unrecorded variety of animal, may or may not actually exist. This is a very complicated question, of course, with strong arguments either way, and we will hence not go into it here. But if it does exist, then the first question to ask about it is “What sort of animal is it?” A truly bewildering array of proposals has been made to answer this question. It has been suggested that Nessie is a colossal otter, or a giant sea slug, or, in fact, a long-necked manatee. And so on. All of the proposals have their own problems, some more severe than others. And none of them have the cultural currency of one particular proposal, one so popular that most people seem to think it is actually the only explanation being offered for a real Loch Ness Monster: the plesiosaur hypothesis.

Trouble is, the idea that Nessie is a plesiosaur may be one of the most hole-filled theories of them all. And as such, the seemingly indelible association of the monster with plesiosaurs may have done more damage to the idea of large, unknown animals living in Loch Ness than all of the arguments brought to bear against this idea, combined.

Let’s look at the problems with the plesiosaur hypothesis, then. There are three very big ones.

1) Plesiosaurs were air-breathing animals. Nowhere in all of evolution has a bloodline redeveloped gills, after having lost them, and anyway there is absolutely no evidence of anything other than air-breathing in plesiosaur skeletons. And the idea that the Loch Ness Monster is any sort of air-breathing animal is, frankly, problematic. Simply put, humans spend a lot of time looking for the Monster. Many, many people have spent hours, days, weeks of their lives with their eyes trained on the loch, looking for any sign of a large animal, without ever seeing a thing. And the idea that an animal – to say nothing of a population of animals – that has to come up for air every now and then could elude such attention is difficult to credit. If there are large animals living in the Loch, their elusiveness strongly suggests that they very rarely surface, and therefore, that they get their oxygen from the water.

2) Plesiosaurs were reptiles. Now, a lot of exciting things have been happening in dinosaur paleontology lately; dinosaurs have been getting better – more active, more intelligent, warm-blooded, and so on. But plesiosaurs were not dinosaurs. They were members of an entirely different branch of the reptile class, one with none of the indications of warm-bloodedness found in the dinosaurs. And not only are reptiles cold-blooded – meaning that their body temperature, and hence their level of activity, changes with the temperature of their surroundings – but they are actually worse than other cold-blooded animals at dealing with actual cold. Some fish, amphibians, or the like have evolved methods of coping with low temperatures; the ability to go into healthy dormancy in the cold, for one example, or to breathe through their skins, hence conserving energy, for another. And reptiles don’t develop these abilities. A kind of hibernation may be possible for them, but this of course won’t work underwater, as they would then assuredly drown.

And Loch Ness is in north-central Scotland. It’s filled with peat, causing sunlight to barely penetrate its waters once you get about twenty feet deep. In short, Loch Ness is cold, and cold all year round. It is in fact a terrible, terrible environment for a reptile of any sort. Some cryptozoologists insist, therefore, that Nessie is a plesiosaur that evolved warm-bloodedness. But this is an essentially pointless exercise. If we’re going to change the traits of our proposed identities, we might as well suggest that Nessie is, say, a Yorkshire Terrier that evolved a plesiosaur-like shape. This would be in some ways more plausible than the plesiosaur evolving a different metabolism; warm-bloodedness springs up but rarely in the evolutionary record, whereas gross morphological changes are cheap and plentiful.

3) Plesiosaurs went extinct 65 million years ago. Whenever you bring this little problem up with some cryptozoologists, they will trot out the coelacanth, which was a sort of fish known only from very ancient fossils, until someone caught a live one off the coast of Madagascar. And the moral of the coelacanth is that the fossil record is an imperfect record of the history of life on Earth. Which is certainly true. It is not, however, a worthless record of the history of life on Earth. Prior to the K/T Boundary at 65 million b.c.e., the fossil record is full of dinosaurs and plesiosaurs and pterosaurs; after the K/T Boundary, they’re all gone. This means something. And part of the implication of what it means is that “living Mesozoic animal” ought to be very, very far down the list of explanations for any particular phenomenon.

It is regrettable, then, that such a poor explanation for Nessie as the plesiosaur hypothesis has become so thoroughly intertwined with the idea of it. Especially when there are much more plausible explanations available. We’ll discuss what may be the best of these next.

To be continued

This entry was posted on Monday, May 7th, 2007 at 8:00 am and is filed under The Kessen Run. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.