Geologic Timescale

Precambrian

The oldest and longest part of Earth's history, lasting from 4.6 billion to 541 million years ago.

Ediacarans

The first multicelled animals that appeared in the fossil record almost 600 million years ago, lacking obvious heads, mouths, or digestive organs.

Cambrian

The period that saw the emergence of the first predators like Anomalocaris and the first eyes in trilobites.

Permian

The last and longest period of the Paleozoic Era, lasting 47 million years and ending in a cataclysmic extinction event.

Paleozoic Era

A time of amazing changes and diversity in life on Earth, from the first animals to the first reptiles and plants.

Ordovician

A period with mostly barren land, some algae, fungi, and primitive plants, where the only continent was Gondwana.

Triassic

The first period of the Mesozoic Era, starting 252 million years ago and ending 201 million years ago, marked by the supercontinent of Pangea and the rise of marine reptiles.

Mesozoic Era

The age of dinosaurs, lasting almost 180 million years from approximately 250 to 65 million years ago, including the Triassic, Jurassic, and Cretaceous periods.

Cambrian Explosion

An event about 545 million years ago that led to a sudden diversity in life forms and the creation of major animal groups.

Cretaceous Period

The last and longest segment of the Mesozoic Era, lasting approximately 79 million years and marked by the development of flowering plants.

Cenozoic Era

known as the Age of Mammals, is the most recent era, but the diversity of life during this time is wider