A turtle in the desert During the Triassic period (about 248 to 199 million years ago), most of Earth's land continued to stick together in one big supercontinent, Pangaea. Because [...]
Tertiary period: Large animals evolved like moose Dinosaurs become extinct The Tertiary period begins with the catastrophe that killed off the dinosaurs at the end of the Cretaceous Period, about 65 [...]
Silurian period: Trout swimming When was the Silurian period? The beginning of the Silurian period was about 443 million years ago. Some environmental problem at the end of the Ordovician [...]
The Quaternary Period includes today - big cities and all When was the Quaternary Period? The Quaternary period began about 1.8 million years ago (1,800,000 years ago), coming after the [...]
Two and a half billion years ago, the Archaean Eon ended and the Proterozoic Eon began. Trillions of prokaryote cells lived in Earth's oceans. Some of these cells could photosynthesize their energy [...]
Crocodiles About 290 million years ago, the Carboniferous period ended and the Permian period began. Almost all of the land on Earth grouped together in one big supercontinent we call [...]
The Ordovician period saw the evolution of the octopus At the end of the Cambrian period, about 488 million years ago, most of the plants and animals living on Earth [...]
A dinosaur skeleton from the Jurassic period How the Jurassic period began When the Jurassic period began, about 199 million years ago, a lot of animals had just become extinct [...]
Geological eras: Fossil spider from the Cretaceous era Why do we have geological eras? Geologists divide the history of the Earth into eons and eras. That's so they don't have [...]
In the Hadean Eon, Earth was covered with active volcanoes like this one. Why is it called the Hadean Eon? Scientists named the Hadean Eon after the Greek god Hades, [...]
