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.
Era · Before c. 3000 BC
Prehistory
From the formation of Earth and the age of dinosaurs to the first cave art and monuments, before writing was invented.
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
Chengjiang Biota: China's Early Cambrian Fossil Treasure Trove
Discovered in 1984 and listed as a UNESCO World Heritage Site in 2012, the Chengjiang fossils are one of the most complete records of early animal life.
Prehistory
Pikaia: The Cambrian Chordate and Early Relative of Vertebrates
Pikaia is now regarded as an early stem-group chordate, a distant relative of vertebrates rather than their direct ancestor.
Prehistory
Burgess Shale: Charles Walcott's Cambrian Fossil Discovery
Found in 1909, the Burgess Shale became the most famous record of Cambrian soft-bodied animals and transformed scientific understanding of early animal evolution.
Prehistory
Caledonian Orogeny: The Closing of the Iapetus Ocean
The Iapetus Ocean closed and Laurentia, Baltica and Avalonia fused into the continent of Laurussia, raising a long mountain belt.
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.
Prehistory
First Land Plants: How Plants Colonised the Land
Plants evolved from freshwater green algae, colonised the land and began to create soils, alter the atmosphere and form the basis of land ecosystems.
Prehistory
Eurypterids: The Giant Sea Scorpions of the Paleozoic Era
Eurypterids flourished for more than 200 million years, produced the largest known arthropods, and died out in the end-Permian extinction.
Prehistory
Late Ordovician Mass Extinction: The First of the Big Five
An estimated 85% of marine species died out in two pulses, but the main Paleozoic groups survived and recovered in the Silurian.
Prehistory
Dunkleosteus: The Armoured Giant Fish of the Devonian Seas
Dunkleosteus became one of the best-known early vertebrate predators; it and all other placoderms died out by the end of the Devonian.
Prehistory
Tiktaalik: The Fish That Took the First Steps Toward Land
Tiktaalik became the best-known transitional fossil between fish and tetrapods, showing how fins began to evolve into limbs.