Geologic Time Scale

The most recent era in the geologic time scale, marked by the appearance of new mammals, increased diversity of life forms, and the presence of humans. Flowering plants became the most common.

The extinction of a large number of species within a relatively short period of geologic time.

A method that made the Geologic Time Scale more specific by determining the age of rocks and fossils through the decay of radioactive isotopes.

A method used to determine the age of rocks and fossils by comparing them to other rocks and fossils.

Cretaceous Period, Jurassic Period, and Triassic Period.

The mass extinction event that led to the extinction of the dinosaurs.

The earliest part of Earth's history, covering about 88% of the geologic time scale, before the appearance of complex life.

The emergence of fish, amphibians, and the first reptiles, along with the development of extensive forests.

It provides a framework for understanding Earth's history and the timing of major geological and biological events.

Fossils help to identify and date the different periods and eras in the Geologic Time Scale.