Ebook Skeletal Remains Suggesting or Attributed to Early Man in North America

According to current classification of geological time the Ceno zoic era (the era of modern life) is divided into two periods, the Tertiary and the Quaternary. The former, which is the older, comprises three subdivisions, Eocene, Miocene, and Pliocene, and the latter two subdivisions, Pleistocene and Recent. These periods are indicated in figure 1 in the order of the formations representing them.