49:2.17

It is both amazing and amusing to observe the early civilization of a primitive race of human beings taking shape, in one case, in the air and treetops and, in another, midst the shallow waters of sheltered tropic basins, as well as on the bottom, sides, and shores of these marine gardens of the dawn races of such extraordinary spheres. Even on Urantia there was a long age during which primitive man preserved himself and advanced his primitive civilization by living for the most part in the treetops as did his earlier arboreal ancestors. And on Urantia you still have a group of diminutive mammals (the bat family) that are air navigators, and your seals and whales, of marine habitat, are also of the mammalian order.