Earth’s history stretches back 4.6 billion years to our planet’s birth. Scientists divide this vast span of time into different periods, such as the Jurassic Period, when many of the dinosaurs lived. Here you can see all the periods on a timeline showing the history of life.
THE LINES TELL TALES
The past leaves clues buried in the rock below our feet. Certain types of rock build up in layers (strata) over millions of years. Different layers correspond to different periods in Earth’s history.
The different periods in Earth’s history are named after the layers of rock in which fossils are found. At the Grand Canyon, you can see these ancient rock layers, which get older toward the bottom.
It’s divided into very long stretches of time called eras. These are further divided into shorter stretches called periods, such as the Jurassic and Triassic:
ERAS AND PERIODS
CAMBRIAN: 542–488 million years ago
ORDOVICIAN: 488–444 million years ago
SILURIAN: 444–416 million years ago
DEVONIAN: 416–358 million years ago
CARBONIFEROUS: 358–299 million years ago
PERMIAN: 299–251 million years ago
TRIASSIC: 251–200 million years ago
JURASSIC: 200–145 million years ago
CRETACEOUS: 145–65 million years ago
PALEOGENE: 65–23 million years ago
NEOGENE: 23 million years ago