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Paleontology · deep time, fossil evidence and changing interpretations

A broad, sourced atlas of paleontology, geological time and scientific inference, from Earth's early setting to modern imaging, geochemistry and ancient DNA.

Coverage and limits

Includes all 178 distinct units with numerical boundaries in the current ICS chart dataset: four eons, ten eras, 22 periods, two subperiods, 38 epochs, 101 other ages, and the Precambrian super-eon grouping. The RDF assigns Pridoli both epoch and age rank; it is represented once as the epoch, with the dual assignment documented, rather than counted twice. This includes named and currently unnamed chart subdivisions. Hierarchical ranks overlap by design; they are not conflicting dates. The data reflect the June 2026 calibration changes.

The biological strand surveys microbial evidence, eukaryotes, algae, fungi, Ediacaran organisms, Cambrian animals, marine invertebrates, land plants, fish, tetrapod origins, synapsids, dinosaurs, pterosaurs, marine reptiles, birds, mammals and hominins. It contains individual specimens, named taxa, important deposits and transitions. It is representative, not a catalogue of every paleontological specimen or every described species. Such a catalogue requires collection databases and continuing taxonomic curation. Use the Paleobiology Database, Royal Ontario Museum fossil gallery and linked specimen collections for deeper occurrence-level research.

Scientific interpretation has its own chronology: Steno, Cuvier, Smith, Lyell, Anning, Darwin and later researchers; radiometric dating, extinction hypotheses, anatomical reconstruction, pigment evidence, genomes and revised calibrations. These dates represent changes in knowledge, not the times when the fossil organisms lived. Historical entries are selected milestones, not a claim that European scientific publication marks humanity's first recognition of fossils. Local knowledge, collecting, preparation and the histories of credit remain relevant.

Dates and uncertainty

Deep-time ages are approximate scientific estimates. Ma = millions of years and Ga = billions of years. For one consistent plotting convention, age A years is placed at astronomical Gregorian year 2000 − A, January 1 UTC. This is an approximate reference-year-2000 conversion, not a claim that a fossil formed on a Gregorian day. Standard radiocarbon BP uses 1950 and is a different convention; rounded Ma here are not uncalibrated radiocarbon dates. Modern year-only discoveries use January 1 only as a year anchor. No historical year zero is displayed in BCE/CE notation. Adaptive labels show mya/bya at deep-time scales.

A representative contextual anchor is deliberately labelled. For broad taxon ranges, a midpoint places the entry within its cited record; it does not claim a species originated or went extinct there. First fossil appearances usually constrain a minimum lineage age. Modern specimen labels, research dates, geological ages and uncertain affinities are kept distinct. Do not read a numerical coordinate as greater scientific precision than the source supports. Fossil papers and older museum summaries can use older boundary calibrations; formal unit bands follow ICS, while individual fossil age summaries retain their stated estimates.

Duration policy

No duration ends at today, the research cutoff, or a fabricated modern endpoint. Only the 173 completed units in the ICS data receive duration bands. Their geological endpoints can have numerical uncertainty while remaining definite closed boundaries. The five ongoing units—Phanerozoic, Cenozoic, Quaternary, Holocene and Meghalayan—have start moments only. Living groups such as Homo sapiens, corals, brachiopods and crinoids are not given artificial extinction dates. Fossil occurrence ranges and individual lifespan estimates have not been converted indiscriminately into durations.

How to explore

Use Separate by tags to distinguish fossil record, discovery and interpretation, and geological time scale. Within geology, use geological eon, geological era, geological period, geological epoch or geological age. Biological and method tags provide additional views, including plants, fungi, arthropods, mammals, hominins, mass extinctions, molecular paleontology and contested interpretations. Expand moments for sources, methodological cards and image qualifications.

Useful windows: 4,600–500 mya for early Earth and early life; 550–250 mya for Cambrian through Paleozoic ecosystems; 250–66 mya for Mesozoic evolution; 66–0.01 mya for Cenozoic life; and 1650–2027 CE for discoveries and deductions. Geological bands nest and can be dense: separate by rank and zoom before reading age-level details. Directional arrows connect evidence to its later study; other arcs are thematic comparisons. Neither kind silently asserts direct evolutionary ancestry.

Evidence prioritizes original research, institutional collections, geological surveys, museum specialists, scholarly histories and primary historical texts. Recent selected research extends through 29 October 2026, checked on 4 November 2026. This does not claim a comprehensive survey of every paper published by that date.

Data and image credits

Geological ranks, hierarchy, colors and numerical ages are derived from the International Commission on Stratigraphy chart and its official RDF dataset. Cite: Cohen, Harper, Gibbard & Car (2025), The ICS international chronostratigraphic chart this decade, Episodes 48:105–115, doi:10.18814/epiiugs/2025/025001, with 2026/06 updates. Chart reuse: CC BY 4.0. Record data retrieval separately from claims of scientific certainty; subsequent ICS changes may revise numerical calibrations.

Cover and backdrop: a photographed Jurassic Dactylioceras commune ammonite, one illustrative fossil rather than a proxy for all life. Each selected image has an individual public-domain, CC0 or Creative Commons reuse record. Photographs of mounts, casts and reconstructions are distinguished from original material; later images are not portrayed as discovery photographs. Backgrounds illustrate selected organisms within a closed interval and do not claim that a pictured species spans the whole interval. Duria Antiquior is historical 1830 paleoart. No modifications beyond thumbnail scaling.

347 moments · 4566998001-01-01T00:00:00Z BCE – 2026-10-29T00:00:00Z CE · by @athan · @athan

Moments

  1. Hadean eon begins
  2. Precambrian super-eon begins
  3. Earth accretes: the physical setting for a later fossil record
  4. Very ancient carbon signatures raise disputed claims of life
  5. Archean eon begins
  6. Eoarchean era begins
  7. Paleoarchean era begins
  8. Dresser Formation preserves stromatolites and evidence of inhabited hot springs
  9. Mesoarchean era begins
  10. Neoarchean era begins
  11. Paleoproterozoic era begins
  12. Proterozoic eon begins
  13. Siderian period begins
  14. Atmospheric oxygenation transforms conditions for life
  15. Rhyacian period begins
  16. Orosirian period begins
  17. Statherian period begins
  18. Organic-walled microfossils record early eukaryotic diversity
  19. Qingshania magnifica preserves multicellular organization
  20. Calymmian period begins
  21. Mesoproterozoic era begins
  22. Ectasian period begins
  23. Stenian period begins
  24. Bangiomorpha pubescens supplies an important red-algal calibration
  25. Neoproterozoic era begins
  26. Tonian period begins
  27. Ourasphaira giraldae extends proposed fungal evidence into the Proterozoic
  28. Cryogenian period begins
  29. Ediacaran period begins
  30. Charnia masoni preserves an Ediacaran frond unlike a modern leaf
  31. Dickinsonia body fossils preserve a distinctive Ediacaran organism
  32. Yilingia spiciformis links a segmented body with locomotion traces
  33. The Cambrian radiation expands the visible record of animal body plans
  34. Cambrian period begins
  35. Fortunian age begins
  36. Paleozoic era begins
  37. Phanerozoic eon begins — ongoing
  38. Terreneuvian epoch begins
  39. Stage 2 age begins
  40. Series 2 epoch begins
  41. Stage 3 age begins
  42. Chengjiang preserves an early Cambrian marine community
  43. Haikouichthys illustrates early vertebrate anatomy
  44. Early trilobites reveal mineralized arthropod diversity
  45. Stage 4 age begins
  46. Miaolingian epoch begins
  47. Wuliuan age begins
  48. Anomalocaris canadensis: a radiodont assembled from once-separate fossil parts
  49. Hallucigenia sparsa demonstrates how fossil orientation changes interpretation
  50. Marrella splendens records abundant small arthropods

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