The scientist who studies the history of Earth and its life, especially as recorded in rocks, is a paleontologist.

Here's why:

* Paleontology is the study of prehistoric life, including fossils, trace fossils, and other evidence of past life.

* Rocks are often the primary source of information about Earth's history and the evolution of life. Fossils are preserved in rocks, providing insights into ancient organisms, environments, and climate.

While other scientists might contribute to understanding Earth's history, the specific focus on life as recorded in rocks is what defines a paleontologist.