During the Cenozoic Era, the Earth's continents were in roughly their current positions, although their outlines were different. Over the course of the era, the continents continued to drift apart and the Earth's climate cooled significantly. The Cenozoic Era is divided into three periods: the Paleogene, Neogene, and Quaternary.

The Paleogene Period began 66 million years ago with the extinction of the dinosaurs and ended 23 million years ago. During this period, the Earth's climate was warm and humid, and there was a great deal of volcanic activity. The continents of North America and South America were still connected, and Europe and Asia were also connected. The Indian subcontinent was still in the process of colliding with Asia, and the Rocky Mountains were formed in North America.

The Neogene Period began 23 million years ago and ended 2.6 million years ago. During this period, the Earth's climate began to cool, and there was a significant increase in the amount of glaciation. The continents of North America and South America separated, and the Panama Isthmus formed, connecting North America and South America. The Mediterranean Sea dried up, and the Sahara Desert formed in Africa.

The Quaternary Period began 2.6 million years ago and continues to the present. During this period, the Earth's climate has continued to cool, and there have been several periods of glaciation. The last ice age ended about 10,000 years ago, and the Earth's climate has been relatively stable since then.

The Cenozoic Era is a time of great change for the Earth. The continents have shifted into their current positions, the climate has cooled significantly, and the Earth has become more biodiverse. The Cenozoic Era is also the time when humans evolved and became the dominant species on Earth.