Wednesday, April 21, 2010 DALE DRINNON: Plesiosaurian Taniwhas
[Plesiosaurus Fossil Skeleton above, Please note the shape of the Limb Girdles]
The actual names of the creatures are taboo and must not be mentioned. Thus, I do not know the name of the creature illustrated on the textile. Water tigers are reported in Indonesia but they are referred to as "Dogs" for the same reason that you must not mention them by name.
UPDATE: While researching the latest series of articles on little-known African Cryptids, I came by chance upon a website that collected traditional African designs to be redistributed in artwork such as Rubber stamps. Here is a Mokele-Mbembe design from Dahomey, and it is exactly equivalent to the other possible Plesiosaur designs. This one is not so careful to show the flipper structure but it DOES indicate the vertebrae: there are approx. 20-30 vertebrae each in the neck, body and tail. That is roughly what I had determined from studies of other Longnecks the world over. It should be noted that multiplication of neck vertebrae is a trait that belongs almost exclusively to the Plesiosaurs themselves: placental mammals nearly always have the standard seven cervical vertebrae, including in giraffes.
Friday, January 08, 2010
DALE DRINNON: On "Discosaurus" and the possibility of Plesiosaurian Survival
However, this was some of the vertebrae and not all: Leidy did think the other vertebrae were legitimate and were of that genus, and probably related to that
However, it seems that both genus names are invalid. 'Cimoliasaurus' has been described as a 'garbage taxon' and several nondescript fossils from Europe and Australia have also been ascribed to this genus, much in the same way as the early tendency to call all early canivorous dinosaur finds 'Megalosaurus'
In this case the really interesting thing is that the New Jersey fragmentary Plesiosaur is found in association with Pliocene dolphin fossils, mixed up together and only separated out later, and the Alabama fossils Leidy considered probably the same genus are labelled as coming from the Eocene zueglodon beds. In the case of the New Jersey Greensands, there is independant evidence that they are not only Cretaceous but also Tertiary: another site gives a paper in which several genera of O. C. Marsh's 'Cretaceous' birds from the New Jersey Greensands are actually of Eocene date or later.
The characteristics of these fossils has placed them tenatively in the same family as Cryptocleidus and Muraenosaurus, and they were thought to have been like the Elasmosaurs but with shorter necks. This is also along the lines of what the surviving Plesiosaurs would have to have been to give rise to our Long-necked Sea-serpents: long-necked, but not excessively long-necked, not so specialised as the extreme Elasmosaurs, and generalised enough to be versatile, possibly enough so that they could pursue other avenues of evolution that became open to them.
That makes a good deal of sense and I am willing to arrange the theory of Plesiosaurian survival on those terms alone.
Dale Drinnon said...
It is important to bear in mind that the name "Discosaurus" was invalid even as that name was given to it, that name had previously been given to something else. So the putative Post-Cretaceous Plesiosaur is officially nameless at this point.6:27 AM
There is more on Discosaurus pssibly being from Eocene deposits in the 1981 book "Fossil Vertebrates of Alabama"
I did not see Scott's comment at the time but he is absolutley right and that book was in fact one of my sources.