8 
ILLUSTRATED NATURAL HISTORY. 
Among the amphibious animals, there were creatures of still more extraordinary proportions. 
One of these, the ichthyosaurus, was a fish-lizard, with the teeth of a crocodile, the head of a 
lizard, and the fins of a whale. The plesiosaurus was similar, but still more remarkable. Cuvier 
asserts that its structure was altogether monstrous. To the head of the lizard it united the teeth 
of the crocodile, with a neck of enormous length resembling the body of a serpent ; it had a trunk 
and tail of the proportions of an ordinary quadruped, with paddles similar to those of the turtle 
or whale. Twenty species of this have been discovered, having a general structure like that of the 
ichthyosaurus. A skeleton is to be seen in the British Museum, eleven feet long, and so nearly 
perfect, that the form of the original creature may be readily traced. It was probably carniv- 
orous, and lived in shalloAV seas and estuaries, and breathed the air like the ichthyosaurus and 
our modern cetacea. The vertebrae of the neck are about thirty-three, equal to those of the 
longest-necked bird, the swan. This neck was probably of great use in aiding it to seize upon 
fish beneath the waters, and perhaps flying reptiles and insects. Its tail was so short that it 
could not have been used, like the tail of fishes, to impel the creature rapidly forward, but was 
doubtless employed as a rudder to steer him when swimming, as well as to raise or depress him 
when ascending or descending in the water. Mr. Conybeare, after considering all the character- 
istics of the animal, draws the following inferences with respect to the habits of the plesiosaurus. 
" That it was aquatic, is evident from the form of its paddles ; that it was marine is almost equally 
so, from the remains with which it is universally associated ; that it may have occasionally visited 
the shore, the resemblance of its extremities to those of the turtle may lead us to conjecture ; its 
motion, however, must have been awkward on land, and its long neck must have impeded its 
progress through the water, — presenting a striking contrast to the organization which so admi- 
rably fitted the ichthyosaurus to cut through the waves. May it not, therefore, be concluded — 
since, in addition to these circumstances, its respiration must have required a frequent access 
of air — that it swam upon or near the surface ; arching its long neck like the swan, and occasion- 
ally darting it down at the fish which happened to float within its reach ? It may, perhaps, 
have lurked in shoal water along the coast, concealed among the sea-weed, and, raising its nostrils 
to a level with the surface from a considerable depth, have found a secure retreat from the assaults 
of dangerous enemies." 
The i(/uanodon, whose bones were found in the soil of Tilgate forest, England, was of altogether 
more monstrous proportions, its length ha'ving been probably near a hundred feet. It was, in fact, 
a gigantic lizard, bearing a resemblance to the iguana of Brazil. It is supposed that such an animal 
could only have existed in a hot country, and hence it is concluded that a torrid climate once 
prevailed in England. The large bones of the ignanodon having been evidently filled with 
marrow, this, with the form of the bones of the feet, shows that the animal was adapted and 
designed to move on the land. Its teeth, also, prove that they were remarkably fitted for cropping 
tough vegetable food, such as the clatharia, and similar plants, which are found buried with its 
bones. As the iguana lives chiefly upon vegetables, it is furnished with long and slender feet, by 
which it is enabled to climb trees with facility in search of food ; but no tree could have borne 
the weight of the colossal ignanodon. Its movements must have been confined to the land and 
water, and it is evident that its enormous bulk must have required limbs of great strength. 
Accordingly, we find that the hind feet, as in the hippopotamus, rhinoceros, and other large mam- 
malia, were composed of strong, short, massy bones, furnished with claws, — not hooked, as in the 
iguana, but compressed, as in land tortoises ; thus forming a powerful support for the enormous leg 
and thigh. But the bones of the hands or fore-feet are analogous to those of the iguana,— long, 
slender, flexible, and armed with curved claws ; thus furnishing prehensile instruments fitted to 
seize the palms, arborescent ferns, and dragon-blood plants, which probably constituted the food of 
the iguanodon. 
Another of these fossil mammals was the pterodactyle, whose bones were of such strange con- 
formation, that the first specimen discovered was classed by one naturalist as a bird, by another as 
a species of bat, and by yet a third as a flying reptile. The creature, indeed, combined certain 
characteristics of all three. The head, and the length of the neck, resemble those of a bird ; its 
wings, in proportion and form, are like those of the bat ; while the body and tail approximate in 
