In time they sank and decayed, and nothing is left of them except an occasional impression in stones, in stones now found in deserts and on high mountain peaks. Birdless forests block the sun in uninhabited lands. Insects swirl in the air. And then, in a majestic, bloodthirsty, and mighty heave, the spinal columns of the vertebrates rise as monstrous lizards and fabulous creatures; dragons flinging their fearful bellows up to a steaming sky... Slowly they become birds, birds as light as undreamt dreams. The searing roars become birdsong, whimpering flutes on warm nights.