An Introduction to the Pleurosaur as a potential lake cryptid ancestor candidate

 

One of my passions in cryptozoology is the investigation of various fossil species presumed extinct and trying to match these species against reported eyewitness testimony in cases involving modern sightings of unidentified animals.

 

The assumption I make is that if one decides to pursue the theory that the eyewitness is giving a truthful and reasonably accurate description of the unknown animal, there are many example species already known from the fossil record that make excellent ‘ancestor candidates’ for the animal.  Minor (or in some cases, less than minor) differences may be rationalized by theorizing on possible changes the ancestor species has undergone from the last identified fossil example to present day.  For example, if one uses a species of plesiosaur that is presumed extinct 65 million years ago, one has a 65 million year ‘gap’ to fill in, if one is to propose the theory of the animal’s continued existence.  While these 65 million years greatly decreases the probability of the animal having survived to present day, it increases the time frame for various advantageous evolutionary changes that may have changed the animal’s physical appearance or biological behavior patterns.

 

When one turns their attention to the rich case files of eyewitness testimony of large unknown animals in freshwater lakes around the world, we have several candidates for possible ancestor species that might explain the continued existence of small colonies in deep fjord or residual inland sea lake systems.

 

For example, since the beginning of the Loch Ness phenomenon, the ‘plesiosaur’ has been a popular candidate for a possible ancestor species.  The name ‘plesiosaur’ is used as a term of familiarity to refer in general to species within the superclass plesiosauridae which were characterized as marine reptiles with long necks, small heads, 4 flippers, an oval, wide body and a short tail.  The answer to the difficult question on why such an animal would migrate to a cold fresh water lake from it’s natural habitat in the ocean is not known, and presents a significant stumbling block.  In addition, the probability that such a species has survived extinction without human detection is low, but the large volume of descriptions that describe large, 4 flippered, long necked, bulky bodied animals around the world cannot be ignored, and so long as people keep on describing such traits, the plesiosaur shall remain a strong contender for inclusion in the survivor candidates group.

 

Other examples of potential ancestor candidates also include (in no particular order):

   Zeuglodon/Basilosaur/Archeocete;

   Large amphibians;

   Tanystropheus;

   Marine crocodiles;

   Nothosaurs;

   Pliosaurs;

   Mosasaurs;

   Giant Marine Snakes.

 

I have excluded the Ichthyosaurs from the list simply because there is a lack of sighting reports mentioning their traits, which essentially would involve some sort of ‘giant toothed dolphin’ description.

 

I also tend to exclude pinnipeds from the list due to obvious behavioral patterns that all known species exhibit, leading me to conclude that it is unlikely they would be capable of escaping identification in a lake located in any populated area.

 

Lastly I tend to shy away from ‘giant worm’ theories.  All of this is a personal preference really, and is not the focus of this document.

 

Pleurosaurus

Recently I came across a new species that should be included in discussions on possible ancestor candidates.

 

Pleurosaurus was a fresh water predator that was at least partially endothermic and was characterized by a long serpentine body with reduced limbs.  Interestingly, the trend along the fossil trail was a continued reduction of these limbs and a lengthening of the body over the known track of it’s evolution, a trend that lends itself well to the discussion of candidate cryptid species in lakes that are often described as ‘serpent-like’.

 

 

The tree of life and evolution is a strange and twisting tale that begs a good imagination and an open mind.  The notion that a crocodile has more in common with a hummingbird than a Komodo dragon, for example, is difficult to grasp, but there it is.

 

If one goes back far enough, one arrives at the time when mammals and reptiles diverged.  At this time, the water was indeed quite muddy in those primordial swamps.  There were all sorts of animals that fit into neither category.

 

The pleurosaur resembled a long serpentine crocodile, with small stubby legs.  Sadly, it appears they lost the sail, but made up for it with a most impressive tail.  The animal was almost all tail.  And it was as similar to a crocodile as well, a Komodo dragon is.  It was in all probability just as warm blooded as other Sphecodont kin, and may have given birth to live young.

 

 

Summary

Pleurosaurs were fresh water predators, they were endothermic, they were long and serpentine, and they had short stubby legs.

 

These characteristics lend themselves very well to discussions on just what kind of species could be living today in the deep trench lakes of the world.

 

If one examines sighting descriptions from the excellent Okanagan cases, we have a number of very close encounters with the animal, no doubt due to the heavy boat traffic during the summer months.  In these rare close up encounters, many eyewitnesses report small legs, and they are very specific.  They do not describe paddles.  They describe small stubby ‘dinosaur-like’ legs.  This is what the pleurosaur had.

 

The pleurosaur was also clearly not a ‘traditional reptile’ species and probably did not have the scales associated with such, but may have had a smoother skin more like modern marine mammals.

 

On Vertical Undulation

In many descriptions of lake cryptids, we see catchwords like ‘caterpillar-like’ or ‘vertical undulation’ or ‘vertical hoops’ that moved up and down.  For years this has caused nothing but problems between traditional experts of the zoological sciences and cryptozoologists.  This is because, as any freshman knows, only mammals can undulate vertically. 

 

The issue of propulsion is to me, a matter more related to eyewitness interpretation than steadfast adherence.  Many eyewitnesses report the animal or animals in lake Okanagan, especially if such observation is made by boat close by the animal, as being more ‘corkscrew-like’ rather than ‘undulating vertically’ which receives far too much air play in my honest opinion.  The long whip-like tail of the pleurosaur is certainly capable of corkscrewing.

 

But the biggest stumbling block of all is size.  Sadly, no pleurosaur has been found yet that exceeded 5 feet in length.  We will have to wait and see if this new possible ancestor candidate proves more promising with further study, or falls further out of the circle of probability.

 

Sources:

 

http://www.ucmp.berkeley.edu/synapsids/pelycosaurs.html

 

http://www.kheper.auz.com/gaia/biosphere/vertebrates/lepidosauria/Pleurosauridae.htm

 

http://perso.club-internet.fr/jflhomme/reptiles_secondaire/pleurosaurus.html