Fig. 98.—Skeleton of Ichthyosaurus.
Containing teeth and bones of Fishes in a coprolitic form. One-fifteenth natural size.
It is curious to see to what a degree of perfection has been carried, in our days, the knowledge of the antediluvian animals, their habits, and their economy. [Fig. 98] represents the skeleton of an Ichthyosaurus found in the Lias of Lyme Regis, which still retains in its abdominal cavity coprolites, that is to say, the residue of digestion. The soft parts of the intestinal canal have disappeared, but the fæces themselves are preserved, and their examination informs us as to the alimentary regimen of this animal which has perished from the earth many thousands, perhaps millions, of years. Mary Anning, to whom we owe many of the discoveries made in the neighbourhood of Lyme Regis, her native place, had in her collection an enormous coprolite of the Ichthyosaurus. This coprolite ([Fig. 99]) contained some bones and scales of Fishes, and of divers Reptiles, well enough preserved to have their species identified. It only remains to be added that, among the bones, those of the Ichthyosaurus were often found, especially those of young individuals. The presence of the undigested remains of vertebræ and other bones of animals of its own species in the coprolites of the Ichthyosaurus proves, as we have already had occasion to remark, that this great Saurian must have been a most voracious monster, since it habitually devoured not only fish, but individuals of its own race—the smaller becoming the prey of the larger. The structure of the jaw of the Ichthyosaurus leads us to believe that the animal swallowed its prey without dividing it. Its stomach and intestines must, then, have formed a sort of pouch of great volume, filling entirely the abdominal cavity, and corresponding in extent to the great development of the teeth and jaws.
Fig. 99.—Coprolite, enclosing bones of small Ichthyosaurus.
The perfection with which its contents have been preserved in the fossilised coprolites, furnishes indirect proofs that the intestinal canal of the Ichthyosaurus resembled closely that of the shark and the dog-fish—fishes essentially voracious and destructive, which have the intestinal canal spirally convoluted, an arrangement which is exactly that indicated in some of the coprolites of the Ichthyosaurus, as is evident from the impressions which the folds of the intestine have left on the coprolite, of which [Fig. 100] is a representation. In the cliffs near Lyme Regis coprolites are abundant in the Liassic formation, and have been found disseminated through the shales and limestones along many miles of that coast.
