The tracks have been found in more than twenty places, scattered through an extent of nearly 80 miles from north to south, and they are repeated through a succession of beds attaining at some points a thickness of more than 1000 feet. The bipedal impressions are, for the most part, trifid, and show the same number of joints as exist in the feet of living tridactylous birds.
Had he been created an erect, bipedal animal, as we find him, his structure would have been not in partial, but in perfect, adaptation to the conditions of that attitude.
In the bipedal position it becomes lowest and most exposed; hence the much greater frequency of hernia in the human species as compared with any of the animals. Another fragment, of the impertinence of whose presence many of us have had painful proof, is the third or last molar, so absurdly misnamed the wisdom tooth.
A comparison of the hind-limbs of birds with those of bats and pterodactyls suggests strongly that the patagium flyers have arisen from arboreal or climbing animals, while the birds arose from terrestrial forms which acquired the bipedal habit, as certain reptiles have. An arboreal animal would necessarily use all four limbs, as climbing animals actually do.
In fact, there can be no reasonable doubt that one of the smaller forms of the Ornithoscelida, Compsognathus, the almost entire skeleton of which has been discovered in the Solenhofen slates, was a bipedal animal.
Entering trees, plants, and other vegetable substances, water, air, earth, and space, that same watery seed of life assumeth the quadrupedal or bipedal form. This is the case with all creatures that you see. "Ashtaka said, 'O tell me, I ask thee because I have my doubts. Doth a being that hath received a human form enter the womb in its own shape or in some other?
Broca, Prof., on the occurrence of the supra-condyloid foramen in the human humerus; anthropomorphous apes more bipedal than quadrupedal; on the capacity of Parisian skulls at different periods; comparison of modern and mediaeval skulls; on tails of quadrupeds; on the influence of natural selection; on hybridity in man; on human remains from Les Eyzies; on the cause of the difference between Europeans and Hindoos.
If it be an advantage to man to stand firmly on his feet and to have his hands and arms free, of which, from his pre-eminent success in the battle of life there can be no doubt, then I can see no reason why it should not have been advantageous to the progenitors of man to have become more and more erect or bipedal.
Thus gazed these two strange beings at each other, held by sympathy and curiosity. Neither had the power of speech, and hence neither could lie to the other. Was it instinct which made Romulus believe that of all the bipedal devils which infested the face of the earth there was one of so gentle spirit that it could love him?
We will now describe some of the highly specialized orders peculiar to the Mesozoic. Some were far larger than elephants, some were as small as cats; some walked on all fours, some were bipedal; some fed on the luxuriant tropical foliage, and others on the flesh of weaker reptiles.