Every entry in stratigraphic order
The 200 entries of Deep Time, grouped by the unit of the geological time scale they belong to, oldest first.
Hadean11 entries
- The Formation of the Earth~4.54 billion years ago
- The Magma Ocean~4.5 billion years ago
- The Giant Impact That Formed the Moon~4.5–4.4 billion years ago (debated)
- Earth's First Atmosphere~4.45 to 4.3 billion years ago
- The Origin of Earth's Water~4.5 to 4.4 billion years ago (origin debated)
- The Jack Hills Zircons~4.4 billion years ago
- The Origin of Earth's Gold~4.4 billion years ago
- Amino Acids in Meteorites~4.3 billion years ago
- LUCA: the Last Universal Ancestor~4.2 billion years ago (estimates 4.3 to 3.5 Ga)
- Alkaline Hydrothermal Vents~4.2 billion years ago (setting debated)
- The RNA Worldbetween 4.4 and 3.8 billion years ago (if it existed)
Archean20 entries
- The Acasta Gneiss: Oldest Rock~4.03 billion years ago (older claims to 4.3 Ga)
- Earth's Magnetic Field~3.9 billion years ago (claims reach 4.2 Ga)
- The Late Heavy Bombardment~3.9 billion years ago (existence disputed)
- The Oldest Traces of Life~3.7 billion years ago (claims 3.95–3.5 Ga)
- Banded Iron Formations~3.5 to 1.8 billion years ago
- Komatiites: the Hottest Lavas~3.5 to 2.7 billion years ago
- The Methane Greenhouse~3.5 to 2.4 billion years ago
- The Proof of an Oxygen-Free Atmosphere~3.5 to 2.4 billion years ago
- The First Methanogens~3.46 billion years ago
- The Oldest Reef: Built by Microbes~3.43 billion years ago
- Photosynthesis Without Oxygen~3.4 billion years ago
- The First Life on Land~3.22 billion years ago
- Nitrogen Fixation and Nitrogenaseat least 3.2 billion years ago
- The First Continents~3.2 to 2.5 billion years ago
- Oxygenic Photosynthesis~3.2–2.8 billion years ago
- The Start of Plate Tectonics~3 billion years ago (estimates 3.8 to 2.2 Ga)
- Pongola: the First Ice Age~2.9 billion years ago
- The Witwatersrand Gold Field~2.9 to 2.78 billion years ago
- Oxygen Before the Great Oxidation~2.7 to 2.5 billion years ago
- The Contested Whiff of Oxygen~2.5 billion years ago (disputed)
Siderian3 entries
Rhyacian4 entries
Orosirian7 entries
- Vredefort: the Largest Crater~2.02 billion years ago
- Asgard Archaea: Our Closest Kin~2 billion years ago
- The Nineteen-Hour Day~2 to 1 billion years ago
- The Origin of the Chloroplast~1.9 billion years ago
- Endosymbiosis and the Mitochondrion~1.9 billion years ago (order of events debated)
- Sudbury: the Crater Turned Mine~1.85 billion years ago
- The End of Banded Iron~1.85 billion years ago
Statherian7 entries
- Columbia: the First Supercontinent~1.8 to 1.4 billion years ago
- The First Eukaryotes~2.0–1.8 billion years ago
- The Boring Billion~1.8 to 0.8 billion years ago
- Euxinia: the Sulfidic Ocean~1.8 to 0.8 billion years ago
- Oklo: the Natural Nuclear Reactors~1.7 billion years ago
- Protosterols and the Lost Eukaryotes~1.64 billion to 800 million years ago
- The Earliest Multicellular Algae~1.6 billion years ago
Calymmian3 entries
Stenian4 entries
Tonian4 entries
Cryogenian4 entries
Ediacaran9 entries
- Cap Carbonates After the Snowball~635 million years ago
- The Doushantuo Phosphate Boom~630 to 574 million years ago
- The Doushantuo Embryos~609 million years ago
- The Gaskiers Glaciation~581 to 580 million years ago
- The Ediacara Biota~575 to 539 million years ago
- The Shuram Excursion~574 to 567 million years ago
- The First Animal Trails~560 to 539 million years ago
- The End of the Ediacara Biota~550 to 539 million years ago
- Cloudina and the First Skeletons~550 million years ago
Cambrian8 entries
- The Small Shelly Fossils~539 to 521 million years ago
- The Cambrian Explosion~540–518 million years ago
- Archaeocyaths: the First Reefs~525 to 510 million years ago
- The Cambrian Substrate Revolution~521 to 509 million years ago
- The First Vertebrates~518 million years ago
- Cambrian Lagerstätten and Soft Bodies~518 to 500 million years ago
- The First Eyes~515 million years ago
- Conodonts: the First Teeth~515 million years ago
Ordovician4 entries
Silurian3 entries
Devonian12 entries
- The Devonian Nekton Revolution~410 to 360 million years ago
- The Coiling of the Ammonoid Shell~409 to 393 million years ago
- Arbuscular Mycorrhiza~407 million years ago
- The Rhynie Chert~407 million years ago
- The Invention of Wood~393 to 383 million years ago
- The Devonian Stromatoporoid Reefs~390 to 372 million years ago
- The First Tetrapods on Land~390 million years ago
- The First Forests~385 million years ago
- Dunkleosteus and the Placoderms~382 to 358 million years ago
- The Invention of the Seed~372 million years ago
- The Late Devonian Extinctions~372 to 359 million years ago
- The Late Palaeozoic Ice Age~360 to 260 million years ago
Carboniferous6 entries
- Pangaea~335 to 175 million years ago
- The Age of Giant Insects~330 to 260 million years ago
- The Origin of Insect Flight~325 million years ago (molecular estimates up to 406 Ma)
- The Amniotic Egg~318 million years ago (tracks suggest ~356 Ma)
- Synapsids: the Mammal Line~315 to 300 million years ago
- The Carboniferous Rainforest Collapse~305 million years ago
Permian3 entries
Triassic8 entries
- Reptiles Return to the Sea~250 to 242 million years ago
- The Origin of Feathers~240 to 160 million years ago
- Durophagy: the Shell Crushers~235 to 66 million years ago
- The Carnian Pluvial Episode~234 to 232 million years ago
- Endothermy: the Origin of Warm Blood~233 million years ago
- The First Dinosaurs~233–230 million years ago
- Pterosaurs: the First Fliers~220 million years ago
- The First Mammals~220–205 million years ago
Jurassic5 entries
Cretaceous8 entries
- The First Flowering Plants~140 million years ago (origin debated)
- How Snakes Lost Their Legs~128 to 95 million years ago
- The Origin of Bees~123 to 100 million years ago
- Oceanic Anoxic Events~120 to 94 million years ago
- Coccolithophores and the Chalk~100 to 66 million years ago
- The Cretaceous Thermal Maximum~94 to 83 million years ago
- Dinosaurs of the Arctic~80 to 66 million years ago
- The Deccan Traps~66 million years ago
Paleogene9 entries
- Chicxulub and the End of the Dinosaurs66.0 million years ago
- The Rise of the Mammals~66 to 56 million years ago
- The Palaeocene-Eocene Thermal Maximum~56 million years ago
- The First Primates~55 million years ago
- Onychonycteris: Flight Before Sonar~52 million years ago
- The Origin of Whales~50 to 38 million years ago
- The Azolla Event~49 to 48 million years ago
- The Tibetan Plateau and the Monsoon~40 to 10 million years ago
- The Freezing of Antarctica~34 million years ago
Neogene8 entries
- C4 Grasses and the Grasslands~10 to 3 million years ago
- Sahelanthropus: the First Hominin~7 million years ago
- The Messinian Salinity Crisis~5.96 to 5.33 million years ago
- The Blue Whale: Largest Animal Ever~4.5 million years ago
- Laetoli and the Origin of Bipedalism~3.7 to 3.2 million years ago
- Lomekwi: the Oldest Stone Tools~3.3 million years ago
- The Oldest Homo Fossil~2.8 million years ago
- The Isthmus of Panama Closes~2.8 million years ago (contested)
Quaternary50 entries
- The Quaternary Ice Ages~2.6 million to 11,700 years ago
- Dmanisi: the First Departure~2.1 to 1.8 million years ago
- The Control of Fire~1 million years ago (habitual use by ~400,000 years ago)
- Homo floresiensis: the Hobbit~700,000 to 50,000 years ago
- Neanderthals~430,000 to 40,000 years ago
- The Origin of Homo sapiens~300,000 years ago
- The Denisovans~300,000 to 50,000 years ago
- The Toba Eruption~74,000 years ago
- The First Sea Crossing to Sahul~65,000 years ago
- Out of Africa~60,000 years ago
- The Oldest Cave Art~51,000 years ago
- The Megafauna Extinction~50,000 to 4,000 years ago
- The Domestication of the Dog~23,000 years ago (estimates 40,000 to 14,000)
- The Peopling of the Americas~23,000 to 15,000 years ago (earliest dates disputed)
- The Younger Dryas~12,900 to 11,700 years ago
- The Origins of Agriculture~11,500 years ago
- The African Humid Period~11,000 to 5,500 years ago
- The 8.2 ka Cold Event~8,200 years ago
- Lactase Persistence~7,500 years ago
- The Black Death1347 to 1352 CE
- The Industrial Revolution1750 to 1950 CE
- James Hutton and Deep Time1788 CE
- The First Vaccine1796 CE
- Naming the Geological Periods1815 to today
- Darwin: Descent with Modification1859 CE
- Mendel's Rules of Inheritance1866 CE
- The Sixth Extinctionsince about 1900 CE
- The Chromosome Theory of Inheritance1902 to 1915 CE
- The Discovery of Penicillin1928 to 1945 CE
- Avery and the Role of DNA1944 to 1952 CE
- Radiocarbon Dating1949 CE
- The Great Accelerationsince 1950 CE
- The Structure of DNA1953 CE
- The Age of the Earth1956 CE
- The Keeling Curve1958 to 2016 CE
- The Genetic Code1961 to 1966 CE
- The Molecular Clock1962 to 1965 CE
- Seafloor Spreading and Magnetic Stripes1963 to 1968 CE
- Restriction Enzymes and Cloning1973 CE
- The Archaea: a Third Domain1977 CE
- Sanger DNA Sequencing1977 CE
- The Iridium Layer at the K-Pg Boundary1980 CE
- The Eradication of Smallpox1980 CE
- The Polymerase Chain Reaction1983 to 1985 CE
- Ancient DNA1984 to 2010 CE
- The Montreal Protocol and the Ozone1985 to 2016 CE
- The Human Genome2001 to 2022 CE
- The EPICA Dome C Ice Core2004 CE
- CRISPR Genome Editing2012 CE
- The Anthropocene: an Epoch Refused2024 CE
The columns of time68 entries
A period boundary is a decision before it is a date. Where the decision and the measurement do not agree, the entry for the unit gives the reason.
- Hadean4.54 Ga → 4.03 Ga
- Hadean world4.54 Ga → 4.03 Ga
- Magma ocean4.54 Ga → 4.4 Ga
- Liquid water and anoxic air4.4 Ga → 2.46 Ga
- Archean4.03 Ga → 2.5 Ga
- Archean world4.03 Ga → 2.5 Ga
- Eoarchean4.03 Ga → 3.6 Ga
- Paleoarchean3.6 Ga → 3.2 Ga
- Mesoarchean3.2 Ga → 2.8 Ga
- Neoarchean2.8 Ga → 2.5 Ga
- Paleoproterozoic2.5 Ga → 1.6 Ga
- Proterozoic2.5 Ga → 539 Ma
- Proterozoic world2.5 Ga → 539 Ma
- Siderian2.5 Ga → 2.3 Ga
- Great Oxidation Event2.46 Ga → 2.22 Ga
- Rhyacian2.3 Ga → 2.05 Ga
- Oxygenated world2.22 Ga → 717 Ma
- Orosirian2.05 Ga → 1.8 Ga
- Statherian1.8 Ga → 1.6 Ga
- Calymmian1.6 Ga → 1.4 Ga
- Mesoproterozoic1.6 Ga → 1 Ga
- Ectasian1.4 Ga → 1.2 Ga
- Stenian1.2 Ga → 1 Ga
- Neoproterozoic1 Ga → 539 Ma
- Tonian1 Ga → 720 Ma
- Cryogenian720 Ma → 635 Ma
- Sturtian Snowball Earth717 Ma → 660 Ma
- Landscape of the Sturtian glaciation717 Ma → 660 Ma
- Interglacial660 Ma → 651 Ma
- Marinoan Snowball Earth651 Ma → 635 Ma
- Ediacaran635 Ma → 539 Ma
- Ice-free to temperate635 Ma → 2.6 Ma
- Cambrian539 Ma → 487 Ma
- Paleozoic539 Ma → 252 Ma
- Paleozoic world539 Ma → 252 Ma
- Phanerozoic539 Ma → Today
- Ordovician487 Ma → 443 Ma
- Silurian443 Ma → 420 Ma
- Devonian420 Ma → 359 Ma
- Carboniferous359 Ma → 299 Ma
- Carboniferous forest359 Ma → 299 Ma
- Permian299 Ma → 252 Ma
- Mesozoic252 Ma → 66 Ma
- Mesozoic world252 Ma → 66 Ma
- Triassic252 Ma → 201 Ma
- Jurassic201 Ma → 143 Ma
- Cretaceous143 Ma → 66 Ma
- Cenozoic66 Ma → Today
- Cenozoic world66 Ma → Today
- Paleocene66 Ma → 56 Ma
- Paleogene66 Ma → 23 Ma
- Eocene56 Ma → 33.9 Ma
- Oligocene33.9 Ma → 23 Ma
- Miocene23 Ma → 5.3 Ma
- Neogene23 Ma → 2.6 Ma
- Pliocene5.3 Ma → 2.6 Ma
- Gelasian2.6 Ma → 1.8 Ma
- Pleistocene2.6 Ma → 11.7 ka
- Quaternary2.6 Ma → Today
- Quaternary ice ages2.6 Ma → Today
- Calabrian1.8 Ma → 774 ka
- Chibanian774 ka → 129 ka
- Late Pleistocene129 ka → 11.7 ka
- Mammoth steppe129 ka → 11.7 ka
- Greenlandian11.7 ka → 6,237 BCE
- Holocene11.7 ka → Today
- Northgrippian6,237 BCE → 2,251 BCE
- Meghalayan2,251 BCE → Today