Prehistory
Columbia (Nuna) Supercontinent: Assembly and Breakup
Most of Earth's continental blocks joined into one landmass, which fragmented gradually between about 1.5 and 1.3 billion years ago.
Region
Worldwide
Prehistory
Origin of Eukaryotes: The Rise of Complex Cells on Earth
A partnership between an archaeal host and a bacterium produced the complex cell, ancestor of all animals, plants, fungi and protists.
Prehistory
The Boring Billion: Earth's Quiet Middle Age in the Proterozoic
Climate, ocean chemistry and oxygen levels stayed relatively stable for roughly a billion years while eukaryotes diversified only slowly, before the upheavals of the Neoproterozoic.
Prehistory
Rodinia: The Supercontinent Before Snowball Earth
Most of Earth's continental crust was joined in one landmass, whose breakup opened new oceans and may have helped trigger the Cryogenian Snowball Earth glaciations.
Prehistory
Snowball Earth: The Cryogenian Global Glaciations Explained
Two long glaciations, the Sturtian and the Marinoan, covered much or all of the oceans in ice before greenhouse warming ended them, setting the stage for the Ediacaran Period.
Prehistory
Ediacaran Biota: Earth's First Large Complex Organisms
The first assemblages of large, multicellular organisms appeared in the oceans, including some of the earliest animals, before most forms vanished near the start of the Cambrian.
Prehistory
Gondwana: The Great Southern Supercontinent and Its Breakup
Gondwana assembled by about 500 million years ago, joined Pangaea, and broke apart from about 180 million years ago into today's southern continents.
Prehistory
Paleozoic Era: From the Cambrian Explosion to the Great Dying
Life spread from the sea onto land and diversified enormously before the era ended with the largest mass extinction in Earth's history.
Prehistory
Cambrian Explosion: The Sudden Rise of Animal Life on Earth
Within some 20 to 30 million years, most major animal body plans, including arthropods, molluscs and chordates, appeared in the fossil record.
Prehistory
Trilobites: The Iconic Arthropods of the Paleozoic Seas
Trilobites diversified into more than 20,000 known species before dying out in the Permian–Triassic extinction about 252 million years ago.
Prehistory
Anomalocaris: The Strange Apex Predator of the Cambrian Seas
Recognised in 1985 as a single animal rather than several, Anomalocaris became the best-known member of the radiodonts, early relatives of the arthropods.
Prehistory
Great Ordovician Biodiversification Event: Life's Second Boom
Marine diversity rose several-fold and the brachiopod-crinoid-bryozoan ecosystems that dominated Paleozoic seas were established.