1. Precambrian Era: This is the longest era, spanning from Earth's formation about 4.5 billion years ago to 541 million years ago. It's further subdivided into the Hadean, Archean, and Proterozoic eons.

2. Paleozoic Era: This era lasted from 541 million to 252 million years ago. It is known for the Cambrian Explosion, a period of rapid diversification of life, and the later appearance of the first vertebrates and land plants.

3. Mesozoic Era: This era lasted from 252 million to 66 million years ago and is often called the "Age of Reptiles". It's known for the rise and dominance of dinosaurs, the emergence of flowering plants, and the eventual extinction of the dinosaurs.

4. Cenozoic Era: This is the current era, starting 66 million years ago and continuing to the present. It is often called the "Age of Mammals" due to their diversification and success following the extinction of the dinosaurs.