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Sunday, 4 August 2013

Another look at 'Giant Sea Slug' Sea Serpents

Creature of the Month The Sinuous Sea-Serpent by Oberon Zell Ravenheart

[end sections of article]

      In 1892, when Oudemans conducted his analysis of 166 Sea-Serpent sightings, the sciences of both paleontology and marine biology were in their infancies, and many creatures now well-known had not yet been officially discovered or recognized by science. Some of these may be significant contributors to reports of then-unknown monsters, and I believe it is time to reevaluate some of these early categories and propose new identifications.
      After we have done with the rotting carcasses, several likely contenders for the real identity or identities of Sea-Serpents are: seaweed masses; giant squids; oarfish; frilled sharks; huge crocodiles and lizards; and seals. But before we examine these possibilities, we have to address the matter of scale. Many written descriptions and drawings of Sea-Serpents match the proportions of known creatures, except for one glaring factor—their immense size. Witnesses often report creatures resembling eels, seals, or otters, but at exaggerated sizes many times greater than that which such animals are known to attain. How can we account for this discrepancy of scale?
      In February of 1985, as our dive boat, the Reef Explorer, was crossing the Solomon Trench on the way from Australia to New Guinea in search of Mermaids (see my previous entry on “Merfolk”), we encountered a true monster of the deep. A huge whale shark appeared right beside our boat, just beneath the surface. I was the first to dive into the water and swim alongside this giant fish, until it eventually descended beyond my range, seeming to simply grow smaller and smaller in the crystal-clear water until it appeared to be but a tiny minnow. Back on the boat, we all compared impressions. There was no doubt in most of our minds that the immense creature must have been at least 40 feet long. Our skipper, however, had a bit more experience with such matters. He had noted the length of the shark in comparison to the boat, and he confirmed that it had been “only” about 20 feet long.

                                Fig. 27. Diagram: size perceived according to distance, by angles (author)
      There are two perceptual factors at work here. The first is pretty straightforward: In the open ocean, as in the sky, there is little objective basis for comparison. Binocular vision only works over short distances. A creature flying overhead could, for all you know, be 100 feet above and have a five-foot wingspan; or, it could be 1,000 feet above and have a 50-foot wingspan. If the air is clear, there is almost no way to know. The same thing is true on the ocean. In the absence of some object of known dimensions at the same distance, a shape in the water could be of any size, depending on how far away you estimate it to be. Moreover, a swimming creature may leave a long wake, which would create the added semblance of a greatly extended tail.
      The second factor is even more interesting, in that it has more to do with our emotional reactions than to what we actually see. It seems we have a kind of built-in “zoom lens” in our brains that automatically responds to anything visually alarming or potentially threatening by zooming in to enlarge it, and simultaneously blanking out everything else. The effect of this tunnel vision is that such things are suddenly perceived as being much bigger than their actual size. I used to encounter this all the time when I lived in a wilderness homesteading community. Rattlesnakes were fairly common on the land, and whenever there was one spotted in an area where children might encounter it, someone would call me to come and remove it, as I knew how to handle them safely. Every time, I would be told about some “huge snake—at least six feet long!”only to discover it was just a little guy, at most half that size. In fact, the snakes even grew larger with each retelling of the story, which greatly enhanced my reputation as a snake handler!
      This is just the way our minds work, after millions of years of evolution, to draw our attention to anything that might threaten our survival. And I am certain that the same perceptual distortion plays a large part in reported sightings of oversize monsters.
Other Seals
      Descriptions and depictions of the Merhorse, with its mammalian whiskers and large, friendly eyes, can be matched with only one known class of animals: seals and sea lions—particularly the Common Seal (Phoca vitulina) and the Grey Seal (Halichoerus grypus). These animals frequently adopt a distinctive “periscope” posture, in which they rise vertically as far as possible out of the water, holding their front flippers tightly against their sides and keeping their heads at a 90-degree angle so as to obtain a maximum view over the waves. The effect looks uncannily like the head and neck of a horse, dominated by the enormous eyes of these pinnipeds. [The grey seal is even dialectically called the Horsehead-DD] The analogy is further enhanced when the animal rises up through a mat of seaweed, which then falls about its head and neck like the mane of a horse (or the hair of a Mermaid…).

Fig. 39. [Hypothetical]Seal in “periscope” position.

      However, it would not be prudent to consign all sightings of “horse-headed” monsters of seas, lakes, lochs, or bogs to sightings of seals. Many of these—especially when they are equipped with several prominent humps—appear to be something else entirely, and are thus more properly referred to as long-necked Sea-Serpents (or Lake-Monsters).[Problem: the humps are also illusionary waves] 

The Great Mystery Remains
      Although I believe that the categories of living animals enumerated above may satisfactorily account for many sightings of the great Sea-Serpent, they also serve to clear the decks for the remaining true unknown monster of the sea—namely, the long-necked Sea- Serpent. I cannot accept the proposal by Oudemans and Heuvelmans, and the other cryptozoologists who have followed them, that these creatures are some sort of gigantic, long-necked, benthic pinnipeds. Although I too found the idea appealing when I first read In the Wake of the Sea-Serpents over 40 years ago, I eventually had to conclude that this explanation really didn’t work. After all, pinnipeds are air-breathers that spend a good part of their lives out of the water. Unlike cetaceans or even sirenians, which are fully adapted to an aquatic life and cannot return to land, all pinnipeds congregate conspicuously in coastal colonies to bask, breed, and nurse their young on rocky shores and beaches. Thus, no species of pinniped—known or unknown—could remain hidden today.            
I have come to believe that long-necked Sea-Serpents are not mammals at all, nor plesiosaurs, nor even vertebrates. Despite his charming reconstruction of a long-necked seal, Heuvelmans’ silhouette drawings based on actual eyewitness descriptions do not exhibit the proportions of his model, nor do they support his pinniped hypothesis, any more than they resemble a plesiosaur; against which identification all the arguments in the previous paragraph also apply.

Fig. 40. Three giant slug Sea Serpents: A. Ingoy Sea-Serpent, 1910, by R. Eliassen;
B. Ingöy Sea Serpent, 1910, after H. Hodgson;
C. Two views of the Cuba Sea-Serpent, after Capt. P. Maguerez, 1934.

      Rather, the common description of the reported Long-Necked Sea-Serpents seems exactly similar to that of the classic Lake-Monsters I examined in a previous entry in this series, and I believe them to be a larger marine variant of these same creatures. That is, some sort of enormous aquatic slug, characterized by a long, extensible neck with diamond-shaped “fins” at its base, and a large, bulky body topped with a series of keeled humps, whose number increases with the size of the animal itself. The proportions of the head and neck are similar to those of a horse, camel, or giraffe, and the hornlike projections atop the head are certainly the eyes and feelers common to all snails and slugs. The rear parts and tail are seldom seen, and thus are poorly described. Probably there are parapodia—fleshy growths resembling wings that are used as fins in swimming. These appendages occur in several known Opisthobranch suborders, such as the Thecosomata and Gymnosomata, and would seem to fit the few observations of the hind parts of Long-Necked Sea-Serpents.

Fig. 41. Reconstruction of Sea-Serpent as giant marine slug, by author.

I think that the best evidence in favor of this hypothesis is the remarkable pair of photographs of Morgawr, the Cornish Sea-Serpent, taken by “Mary F.” in February of 1976, from Rosemullion Head near Falmouth Bay. (Fig. 42) In her letter to the Falmouth Packet, which published the photos, Mary F. said that the monster was only visible for a few seconds, and that the part she could see was about 15–18 feet long: “It looked like an elephant waving its trunk, but the trunk was a long neck with a small head on the end, like a snake’s head. It had humps on the back which moved in a funny way. The color was black or very dark brown, and the skin seemed to be like a sealion’s…the animal frightened me. I would not like to see it any closer. I do not like the way it moved when swimming.”

Fig. 42. Morgawr, the Cornish Sea-Serpent, photographed by “Mary F.” 
in February, 1976, from Rosemullion Head near Falmouth Bay.

      In December of 2006, a giant squid was captured alive and videotaped as it thrashed about at the surface. Prior to that moment, no living specimen of the legendary Kraken had been witnessed in modern times, and all we knew of them was from rotting carcasses washed up on beaches. Perhaps someday a living long-necked Sea-Serpent will also be captured in a net or on video, and we’ll finally know for certain what they are.
      Meanwhile, it’s good to know that there still remain some unsolved mysteries of the deep.

-Once again we have the same tired old (ignored) objection that an invertebrate animal needs some internal structure (skeleton)in order to be able to keep its shape when standing up out of the water or when travelling on land. The "Periscope" head and neck is an especial problem in this regard, an invertebrate creature has not enough muscular strength to keep such a structure bonelessly aloft. This author seems tothink that vagueness of description and missed details mean that those details are not there and have not been described by other witnesses. In this case we are talking about distinct rear limbs and tail sections, making an overall Plesiosaurian shape in the cleaer observations. And then there is the matter of the head. Ravenheart seems to imply that simply because some sightings cannot make out the head very well the head must be actually featureless. Nothing could be further from the truth. As a matter of fact, there are a number of very exacting observations f the head for the Loch Ness Monster and the Great Sea-serpent which are consistently and repeatedly described. The head is flattened on the top, making the head wider than it is thick. Since the neck is circular in section this means that the head is as thick through as the neck in profile (meaning no obvious visual differentiation in many sightings) but that the head is wider than the neck when seen from above and, since the mouth splits the head in two, the width of the mouth is wider than the width of the neck. The thickness of the whole head, mouth closed, is about half the length of the head and the width of the head is about 2/3 of the length. The eyes are about halfway along  the top in profile with the nostrils immediately in front of them, the line of the mouth runs back behind the position of the eyes (some sightings miss this point) and the lower jaw is hinged on at the rear end  of the skull. The whole length of the head is approximately 1/20 of the animal's entire length, and therefore it is not unreasonable the details and the features might not be so obvious as the rest of the animal.  Oudemans, Heuvelmans, Gould and Dinsdale agree on these features but only Oudemans states these features specifically and statistically The description is a very good match for a Plesiosaur's skull: Heuvelmans specifies several of these features when discussing the "Merhorse" reports (as opposed to the "Juvenile Merhorse" reports which correspond to the seal category as mentioned above: the "Adult" features additional include that the head is very flat on top and wide fro the front, looking like a snake's head.) Gould also states this shape of the head in detail in connection to Captain Haslefoot's sighting of The Loch Ness Monster in the 1930s, and also the part about the very wide mouth that goes with the wide flat head. Since we have these very specific and regularly repeated statements, the featureless head (and the main reason for the giant slug theory) falls by the wayside. DD .

Just for the record, Here are the composites from the statistics again, I shall probably do a more in-depth discussion of these later.
(Eyes are representatonal, usually reported as heavy-lidded or even with eyes closed
The area shown does seem to be the size of the eye sockets )
Below, the proportions of head, neck and body when more carefully noted
This is to be compared and contrasted to the vaguer series of sightings illustrated in the article above



  1. The photos alleged to be of the Cornish sea serpent mogawr look suspiciously like an elephant waving its trunk, don't they?

    1. Actually, no. Those are the words of the author, but the comparison is forced.
      The neck does not mechanically correspond to an elephant's trunk, nor is it attached on the same way, nor yet is it especially different from the Longneck's usual arched fishing posture (as has been alleged): all you have is some movement at the end of the neck, otherwise stated to be the most flexible part of the neck. It basically only just straightens out at the end. Not good evidence for any suspected excessive flexibility if that is your insinuation.

  2. You think these photos are genuine, then?

  3. You astonishing man. What I sais was that your statement that the head and neck looked like an elephant's trunk was wrong. I never said the photos were necessarily real. I like to keep that option open, though. The body is so very high out of the water that it looks peculiar, unless it is sitting on a submerged sandbar or something

  4. Oberon Zell Ravenheart has responded to some of your criticisms of the giant marine slug as sea serpent hypothesis (look at the comments section of his article on

    1. Well you are just going to have to produce an actual working link, aren't you? Has Zell a working practical knowledge of physics or experience with the dead bodies of extant giant invertebrates (ie, giant squids, which always flatten out to virtually only carpets of organic matter when pulled free of the support of the sea?) If not, I'm afraid his input is only going to be about as useless as yours usually is.

  5. It says on Zell's profile that he is a naturalist, among other things.

    1. I still do not know what sort of a reply he has made, you have provided no quote and no link. I have no way of responding with a rebuttal since I have no way of knowing what the man is supposed to have said in response to my remarks (in a formal debate that would be the end of it, by the way: I get one more round and he gets no more rounds). And calling oneself a "Naturalist" hardly qualifies as having adequate credentials.

  6. Zell said that a longnecked sea serpent's "periscope" is held above the water in the exact same way a snail keeps its head aloft.

    He also said that since slugs and other gastropods are powerfully muscled, a giant marine slug would be able to keep its shape while traveling across land.

    1. The reason I mentioned physics is because of the well-known principle called the square-cube law. Increase the size of a creature by several times and you are increasing its mass in three dimensions BUT since muscle only pulls in one direction, the muscular strength never keeps up with the increased weight. The mass increases as the cube of the increase but the muscular strength only increases by the square, and this is frequently given as the reason why you do not have giant humans or grasshoppers or any other of that 1950s B-Movie sort>

      It is clear that he does NOT know of the law, he did not understand the problem and the answer is woefully inadequate. And furthermore, I fully expect he will not even realize why his answer is inadequate should you point this out to him again. That will not mean that he has won any sort of an argument, it shall merely point out why it is useless to debate the matter any further with him.


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