ICHTHYOSA URIA 1 23 



sions or molds of it that have been discovered in the rocks, in which 

 many fine creases are seen, but nothing suggesting scales or bony 

 plates, save on the front edge of the paddles, where impressions 

 of overlapping scales have been observed. This is an interesting 

 fact, bearing witness that their land ancestors had been covered 

 everywhere with scales, much like those of existing lizards and 

 other reptiles. Scales or bony plates were not only useless to the 

 ichthyosaurs in the water, since they could afford no protection, 

 but would have been detrimental in increasing the resistance in 

 swimming. 



That the ichthyosaurs were predaceous animals is of course 

 evident from their teeth, adapted for the seizure and retention of 

 sHppery prey, but not for tearing or comminuting. The fossilized 

 remains of food found between the ribs of some specimens, in the 

 place where the stomach was, together with fossil excrement, 

 called coproUtes, usually attributed to these animals, prove that 

 they fed largely upon fishes, squids, belemnites, and probably 

 other invertebrates. One ichthyosaur specimen preserved in the 

 Stuttgart Museum has preserved in its stomach contents a mass 

 composed of the remains of more than two hundred belemnites. 



Most interesting of all is the fact that, not very rarely, embryonic 

 skeletons of ichthyosaurs have been found associated with the 

 remains of adult animals, in such positions that they must have 

 been inclosed within the body cavity at the death of the animals. 

 As many as seven such embryonic skeletons have been observed 

 with a single specimen. At first it was supposed that these skele- 

 tons were of small ichthyosaurs which had been swallowed whole 

 as food, since it is not at all likely that these predaceous reptiles 

 were discriminative in their choice of food when hungry. It is not 

 improbable that in some cases this is the true explanation of the 

 smaller skeletons within the larger ones, but it cannot be true of all, 

 since wherever the small skeletons are identifiable they have been 

 found to belong to the same species as the adult, and it would 

 be absurd to suppose an ichthyosaur bent upon its prey would be 

 at all likely to select as many as seven young animals, all of the same 

 size and all of its own species. Furthermore, some of these young 

 skeletons have been found in such positions as would indicate that 



