The Cenozoic Era marked the end of the dinosaurs and the emergence of mammals and birds. Although primitive mammals and birds first appeared in the Mesozoic era, it was not until the Cenozoic Era that they really emerged as powers in the world. Please click colored blocks for more information. .
The Cenozoic Era is divided into two major periods.
• The Tertiary Period, starting 65 million years ago, saw the end of the dinosaurs and the great rise of mammals and birds to take the place of the dinosaurs. Many of the creatures from the Tertiary Period are direct ancestors of modern species. .
• The Quaternary Period, which began just 2 million years ago, marked the origin of humans as well as the modern forms of the animals we see today. .
Cenozoic means "new animal life", and the Cenozoic Era, which includes the present day, is characterized by fossils that resemble living animals. Modern types of mollusks, echinoderms, corals, and arthropods are the dominant marine invertebrates, and mammalian groups such as whales and dolphins replaced marine reptiles of the Mesozoic. Cenozoic land faunas are dominated by mammals and birds and angiosperms dominate floras. The last one million years of the Cenozoic, known as the Quaternary Period or Ice Age, records a cooling of climate and four major episodes of glaciations.
The Cenozoic Era spans only about 65 million years, from the end of the Cretaceous Period (Mesozoic Era), and the extinction of non-avian dinosaurs, to the present. The Cenozoic is sometimes called the Age of Mammals, because the largest animals found on land during this time have been mammals. This is a misnomer for several reasons. First, the history of mammals began long before the Cenozoic Era began. Second, the diversity of life during the Cenozoic is far wider than mammals. The Cenozoic could also be called the "Age of Insects," "Age of Teleost Fish," "Age of Birds," or the "Age of Flowering Plants" just as accurately.
