Ancient Climates

So far in our brief account of formation of the layers of rock, we have merely mentioned the climate that existed during Oligocene time, the kinds of plants that grew, and the types of animals that roamed the land or lived in the waters.

There is good evidence that at least during the first part of the Oligocene epoch, the climate was comparatively warm and moist. A type of crocodile lived here at that time; palms were present, as were other plants and animals that require a warm, moist environment. Later, these typical warm-weather species vanished from the scene because of changing climatic conditions, and those now commonly found in cooler regions appeared in great numbers.