34 ANIMALS OF THE PAST 



Plesiosaur, there were many species of assorted sizes. 

 The Ichthyosaurs, especially the smaller kinds, were, so 

 to speak, reptilian porpoises, far more so than was 

 imagined, provided, however, with four useful paddles 

 instead of two, in addition to a powerful tail whose 

 shape and use were long unsolved problems. The great 

 majority of the specimens discovered had the last 

 section of the long tail bent at an angle to the rest of the 

 backbone and this was interpreted as indicating the 

 existence of a flattened tail, something like that of a 

 newt or salamander, that "flopped" over in the dead 

 animal, twisting the hinder portion of the tail to one 

 side. And so for many years the Ichthyosaurus was 

 figured with a compressed tail. But when, later on, a 

 finely preserved specimen came to light, lying upon one 

 side and having the tail in place, lo it was much like 

 the taU of a shark, only reversed, the lower lobe being 

 longer than the upper. The meaning of this is that the 

 reptile wished to come to the surface now and then to 

 breathe while the shark goes down in search of food, or 

 to escape from danger. One feature shown in the more 

 perfect specimens was quite unsuspected, and that was 

 the existence of a high back fin precisely like that of a 

 porpoise. 



Buckland described the Plesiosaur as "a snake, 

 threaded through the body of a turtle" and this will 

 serve pretty well for the long-necked species, even 

 though the "shell," or carapace, of the turtle is lacking, 

 the body of the long-necked sea reptile apparently 

 having been covered with smooth skin. Whether or not 

 the snake-like neck had any of the mobility of a serpent 

 is a matter still in dispute, but we would remind those 

 who claim that on account of their biconcave vertebrae 

 the Plesiosaurs must have been a stiff-necked generation, 

 that animals frequently do things that are theoretically 



