Here is the correct order of the major geological eras, from oldest to youngest:

1. Precambrian Era (4.5 billion years ago - 541 million years ago)

- The longest era, encompassing the formation of the Earth and the first appearance of life.

2. Paleozoic Era (541 million years ago - 252 million years ago)

- Characterized by the Cambrian Explosion, the rise of fish, and the first land animals.

3. Mesozoic Era (252 million years ago - 66 million years ago)

- The age of dinosaurs, with the rise and fall of the supercontinent Pangaea.

4. Cenozoic Era (66 million years ago - present)

- The era of mammals, including the evolution of humans.

It is important to remember that these eras are further divided into periods, epochs, and ages. This timeline helps us understand the vast history of Earth and the evolution of life on our planet.