More Comments on Heuvelmans’ Sea-serpents and an introduction to Acrophoca (prehistoric pinniped)

A Continuation to Surviving Plesiosaurs as Longnecked Seals (Longnecked Sea-Serpent candidates) 

(Sydney’s note: This is the continuation of a series of posts by Dale Drinnon over at Frontiers of Zoology, please let me know what you think of these assessments/theories.)

Heuvelmans’ LongNecked Sea-Serpent

This type also features a shorter line of humps on the back which Heuvelmans says are of variable contour: one big central hump on the back, or several medium sized ones (which he says that the big central hump causes the appearance of two or three large humps together) or else the humps are whipped by turbulence waves in the water to as many as six or seven smaller humps in a line. His book In the Wake of the Sea-Serpents includes a plate showing a swimming seal to make the point about the turbulence waves. This follows after earlier suggestions that the humps might be inflatable airsacs, which is a theory Dinsdale championed at first and then Sanderson took up thereafter. Heuvelmans continued the idea the humps might be airsacs in the Many-humped kind and I used to go along with the idea in the case of the Longnecks. Discussions with members at the yahoo group Frontiers of Zoology did bring home the extreme precariousness of the arrangement, when an accidental puncture would be disastrous and too great of water pressure on the whole could blow out the whole system and potentially expose a large section of the back to the mercy of the outside world.

So a safer model might be like the sperm whale’s spermaceti tank removed to the center of the back as a hydrostatic organ in lieu of a back fin. Anatomically it would be composed of mostly the top layer and the bottom layer of tougher connective tissue and in between, a chamber full of an oily or waxy secretion. This would be equivalent to what Heuvelmans was saying when he was calling the hump area a sack of oily fat, which would come down to basically that same structure, anatomically speaking, and it would act the same way to become variable-contour in the water.

However for the most part and for the very LONG hump-trains, we would still be talking in terms of standing wave effects caused by the way the wake works.



Heuvelmans also said that the Longneck occasionally showed “Horns” that were presumably erectile nostrils forming snorkles. I would have to say that the feature occurs so infrequently, and is also known to show up consistently in one category of mistakes, that this feature is unconfirmed. It is best not to make too big a deal over them.



Given that the “Mane” is sometimes said to be spiny, the “Horns” might be nothing more complicated than part of a young male’s first mane starting to come in (They are definitely spoken of as part of the mane in the Corinthian Sea Serpent’s description)

There are on the other hand still good reason to think there are such things as Long-necked seals. In fact they had a scientific description long ago but were mostly forgotten since then.


The Kivik Stone Evidently Illustrated Long-Necked Seals!
The Long-necked seals turn out to be not so very large and still in the size range of the “Known” seals since reports of them are universally between ten and twenty feet long.



Although the photos are not clear, the great distance between the head and the (supposedly turtlelike) body of this sea monster do cause me to think this might be a fairly young Longnecked sea-serpent. This would be about right for the usual attitude in the water, the creature must be putting out some sort of an effort to seem to ride higher in the water, probably by using its paddles in a downstroke. If I understand these photos correctly, the head of the crature at top is facing right and at bottom it is facing left.


Posted by Dale Drinnon July 2011


And now, here is an introduction to Acrophoca in an article written by Austin Whittall from Patagonian Monsters:

Long necked seals in South America

There is a fossil seal, the Acrophoca longirostris (the second part of its name means ‘long face’ in Latin), which lived in the Pacific Ocean by the coast of Peru and Chile during the Miocene and Pliocene periods (23.3 to 2.5 Million years ago). It has been described as a “swan-necked” seal.


Size comparison Long Necked Seal and man.
Adapted from Austin Whittall

As most ‘lake monsters’ are described as having ‘swan necks’, this seal if still alive, would be the ideal candidate to fill in the lake monster’s shoes. Lets get the facts:

Swan-necked seals

First the bad news: according to paleozoologist Darren Naish, they were not so long-necked; thought they would “have looked longer in the neck than any extant seal”. These were not mammalian “plesiosaurs”.

However Acrophoca had longer cervical vertebrae and a cervical column (neck) than modern extant seals.

Their neck measured 32.9 cm (or approx. 1 ft 1 in), while regular monachine seals’ necks are about 21.8 – 24.9 cm (8.6 – 9.8 in.). To express this in another way, the neck of these Acrophoca represented 21% of the length of their vertebral column while in other terrestrial carnivores and seals it is about 17-19%. Not much of a difference.

Based on this, Naish concludes that “sadly, ‘swan-necked seal’ really is a bit of an exaggeration”.

Regarding its placement within the “seal” family it is a hot topic among seal experts and some have suggested that it is a lobodontin and as such belongs to the group that includes the leopard seal (Hydrurga), the crabeater seal (Lobodon) and Ross’ seal (Ommatophoca).

If this was the case, we should look at these living lobodontins to get an idea of their behavior and appearance. Leopard seals are big carnivores (males can measure up to 3.3 m long and weigh close to 450 kg -11 ft and 1,000 lbs.) It is the top predator in its environment with formidable jaws and canine teeth 2.5 cm (1 in.) long. It feeds on penguins, squid and seals of other species.

Naish and Stig Walsh described some remains of Acrophoca discovered in Chile in 2002, which had longer skulls than the A. longirostris. Perhaps more fossils may indeed turn up and give us a clearer picture of this group of seals and its evolution.

From a cryptozoological point of view, this finding (which came from the same site as those of the “walrus”, sea cows Odobenocetops, and the giant sea sloths, Thalassocnus) is very interesting, as a long-necked seal could readily explain many “lake monster” sightings in Patagonia.

Long-necked seals. Some facts

Besides the ‘real’ A. longirostris, there is another “long-necked” seal, one which despite being described by scientists in the seventeenth and eighteenth century, has not been seen again, and therefore remains a mystery. This creature as depicted in the images (above and below) had a very long neck unlike anything seen in other seals.

The image below shows two seals, one, above is the enigmatic “Long neck’d Seal, or Sea Calf”, and the one below is “The common seal”. I have included a seal skeleton for comparison purposes. But first, lets go to the story.


James Parson wrote a paper in 1751 in which he described five “species” of Phoca, among them he mentioned a Dr. Grew’s “long neck’d seal” from an unknown locality. This peculiar seal was actually part of the Royal Society’s Museum, and as such it was included in a Catalog published in 1681, where it was described as follows:

From his nose end to his fore-feet, and from thence to his tail, are of the same measure

Also, “instead of his fore-feet, he hath rather fins; not having any claws thereon, as have the other kinds.” 

Parsons described a ‘young´specimen which measured 7.5 ft. (2,28 m) long. We ignore the size of an adult. However, as can be seen above, the specimen was 41% longer than the ‘common’ seal and its neck and head represented 43% of the total body length (which coincides with Grew’s remarks of 50/50 relationship of nose to fore feet and tail to forefeet). In the common seal, the head plus neck is only 26% of the total body length. Indeed it is a very big “long-necked” seal.

What kind of seal was it? It is generally considered as either a mythical or an indeterminable species. its scientific name, as given by Dr. Shaw in his Zoology(1800) is Phoca longicollis or long-necked seal.

Allen contends that the shape of its front feet and its longer neck, make it an “Eared Seal”, or an “Otaridae”. However Fischer (1827) in his Synopsis) places it with the lobodontins: the Sea-Leopard of Weddell which is an Earless Seal or a “Phocidae”.

Allen also asserts that its habitat though unknown must have been either the Cape of Good Hope or Southern South America because no seals from Australia or the North Pacific reached England before 1686. And states that it may have been a Sea-Lion (Otaria leonina). These are “Otaridae” and have visible ears.

By the way,in 1670 Sir John Narborough explored Patagonia from Puerto Deseado on the Atlantic to Valdivia, in Chile, went through the Strait of Magellan twice and spent part of a winter at San Julián. He could have brought the seal with him. Before his voyage we can only mention Cavendish’s and Drake’s expeditions, but they were more interested in plundering Spanish riches than describing the native fauna.

The Patagonian link

So here we have an earless long-necked seal which may have lived in the Southern reaches of the South Atlantic Ocean, similar to the “sea lion” which can be found on the coasts of Patagonia.

We also have fossil evidence of a “swan necked” seal in Peru and northern Chile, which despite being far from Patagonia, places these creatures in the same part of the globe.

The “long necked” seal is described in Gronovius (1760) Bibliotheca as having a “capite lutrae”, that is “with an otter head” (Bold, mine). This detail combined with the possible geographic location, its long neck, lack of ears and size make it a likely candidate to embody our mysterious Patagonian iemisch or water tiger, or perhaps our Strait of Magellan Sea Monster.

Now the bad news: we should bear in mind however that iemisch had clawed paws and a long tail. the long-necked seal lacks both (“not having any claws”). So, perhaps some other species within the group could account for our iemisch.

Piling speculation on speculation we can also imagine that it may even have adapted to freshwater (like the landlocked Lake Baikal seals Pusa sibirica or those at lakes Ladoga adn Saimaa have done in Russia) and running upstream from the Atlantic or the Pacific Oceans, made its home and lived in the Patagonian lakes until quite recently.

In my book, based on etymology and some comparisons of the words used by the Mapuches and different Tehuelche Groups to name seals and other aquatic animals, I came upon the possibility of a freshwater seal in Patagonia. Below is an excerpt from my book on this intriguing subject:

Note: Above, the sea wolf (South American Sea Lion) is also known as Lobo Marino de dos pelos) Otaria flavescens. The “sea lion” mentioned by Allen (Lobo Marino de un pelo) or Otaria leonina is also known as Otaria Byronia.

Sources: frontiersofzoology.blogspot.com/search/label/Long-Necked%20Seals, patagoniamonsters.blogspot.com/2010/10/long-necked-seals-in-south-america.html

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