Began with the formation of Earth. This period of Earth's history lasted approximately 2.8 billion years!
Origin of the Earth
This timeline discusses the major key elements of the origins of the Earth. We also go in depth about the Cambrian period that occured during the Paleozoic era. From many perspectives, the early development of the world we live in, is still a mystery to some!
Archean ERA
Did you know?
The bulk of the free oxygen in the Archean atmosphere was derived from organic photosynthesis of carbon dioxide (CO2) and water (H2O) by anaerobic cyanobacteria (blue-green algae), a process that releases oxygen as a by-product. These organisms were prokaryotes, a group of unicellular organisms.
The earliest living cells formed on Earth. These cells all lived in the oceans, which were probably much warmer and more acidic than they are now. By about 3.5 billion years ago, these early cells had evolved into simple prokaryotic cells.
Proterozoic ERA
The Proterozoic era lasted almost two billion years, starting 2,500 million years ago and ending 542 million years ago.
The Earth had cooled considerably from the previous Hadean eon when the planet was covered by molten lava.
Eukaryotic, single cell organisms with a nucleus and membrane, evolved from the more simple cyanobacteria
Many mountain belts formed during the this. It occured in intervals between 2.1 and 1.8 billion, 1.3 and 1.0 billion, and 800 and 500 million years ago, associated with the breakup of continents and the collision of their fragments. New ocean ports were created due to this.
Did you know?
Mountain belts such as the Himalayas contain blocks of Proterozoic rocks many tens of kilometres in size
Paleozoic ERA
It began 541 million years ago with the Cambrian explosion. The Paleozoic takes its name from the Greek word for ancient life.
Several different kinds of organisms adapted independently to life on land, primarily during the middle Paleozoic
Paleozoic rocks are widely distributed on all continents. Most are of sedimentary origin, and many show evidence of deposition in or near shallow oceans
Towards the end of the Paleozoic Era, it eliminated such major invertebrate groups as the blastoids (an extinct group of echinoderms related to the modern starfish and sea lilies), fusulinids, and trilobites
Cambrian Period (occurred in the Palaeozoic era)
Earliest time division of the Paleozoic Era, extending from 541 to 485.4 million. Usually called the "Explosion of Life"