History of Earth

4.6 Billion Years Ago

1 CE

The Earth was formed. It is thought to have formed by collisions in the giant disc-shaped cloud of material that also formed the Sun. Gravity slowly gathered this gas and dust together into clumps that became asteroids and small early planets called planetesimals.

3.8 Billion Years Ago

2

The first life forms appeared on Earth. The history of life on Earth began about 3.8 billion years ago, initially with single-celled prokaryotic cells, such as bacteria.

3.5 Billion Years Ago

3

Oxygen first entered the Earth's atmosphere. Most scientists believe that for half of Earth's 4.6-billion-year history, the atmosphere contained almost no oxygen. Cyanobacteria or blue-green algae became the first microbes to produce oxygen by photosynthesis.

2.7 Billion Years Ago

4

The first eukaryotes appeared on Earth. Eukaryotes are organisms with a nucleus. The oldest evidence of eukaryotes is from 2.7 billion years ago.

600 Million Years Ago

5

More complex forms of life took longer to evolve, with the first multi cellular animals not appearing until about 600 million years ago.

450 Million Years Ago

6

During the Ordovician, most life was in the sea, so it was sea creatures such as trilobites, brachiopods and graptolites that were drastically reduced in number.

360 Million Years Ago

7

Three quarters of all species on Earth died out in the Late Devonian mass extinction, though it may have been a series of extinctions over several million years, rather than a single event.

270 Million Years Ago

8

At this time most of the dry land on Earth was joined into one huge landmass that covered nearly a third of the planet's surface.

200 Million Years Ago

9

Pangea begins to break up. The movement of Earth's tectonic plates formed Pangaea and ultimately broke it apart.

251 Million Years Ago

10

Permian–Triassic extinction event: The Permian mass extinction has been nicknamed The Great Dying, since a staggering 96% of species died out

201.3 Million Years Ago

11

Triassic–Jurassic extinction event: Many types of animal died out, including lots of marine reptiles, some large amphibians, many reef-building creatures and large numbers of cephalopod molluscs. Roughly half of all the species alive at the time became extinct.

66 Million Years Ago

12

Cretaceous–Paleogene extinction event: is famed for the death of the dinosaurs. However, many other organisms perished at the end of the Cretaceous including the ammonites, many flowering plants and the last of the pterosaurs.

1.8 Million Years Ago

13

Homo erectus were the first of the hominina to leave Africa, and these species spread through Africa, Asia, and Europe between 1.3 to 1.8 million years ago. One population of H. erectus, also sometimes classified as a separate species Homo ergaster, stayed in Africa and evolved into Homo sapiens.