Secondly, the nature of the revolutions which have altered the surface of the earth must have had a more decisive effect on the terrestrial quadrupeds than on the marine animals.
Many times when you're a tourist you can just stay on the surface and not really experience the place you're visiting, which will probably leave you disappointed. Everywhere has something interesting; it's just about being curious enough to find it and scratch where you have to scratch and stay longer and walk further.