The end-Triassic mass extinction

Assembled from 28 blocks · 2 evidence · 19 related

1. Story
2. The extinction at the Triassic–Jurassic boundary, coinciding within the resolution of high-precision dating with the main eruptive pulses of the Central Atlantic Magmatic Province as Pangaea began to rift. Conodonts disappear entirely, ammonoids are severely reduced, reef systems collapse again, and on land the crurotarsan archosaurs — the crocodile-line reptiles that had been the dominant large land predators through the Triassic — are almost eliminated. The consequence is the clearest single case in the record of an extinction changing what the world looks like afterwards: dinosaurs had existed for tens of millions of years as one group among several, and it is only after this event that they become the dominant large terrestrial animals. The boundary interval carries carbon-isotope excursions consistent with rapid additions of isotopically light carbon, which is the same signature the end-Permian and the Palaeocene–Eocene warming events show.
3. Knowledge
4. Mass extinction
5. Central Atlantic Magmatic Province
6. The Cretaceous–Palaeogene mass extinction
7. The end-Triassic mass extinction
8. Connections
9. The end-Permian mass extinction
10. Central Atlantic Magmatic Province
11. Mass extinction
12. The Cretaceous–Palaeogene mass extinction
13. The end-Triassic mass extinction
14. Radiometric dating
15. The end-Permian mass extinction
16. The Cretaceous–Palaeogene mass extinction
17. The end-Ordovician mass extinction
18. The Late Devonian crisis
19. The end-Triassic mass extinction
20. The Cretaceous–Palaeogene iridium anomaly
21. Chicxulub impact crater, Yucatán
22. Mass extinction
23. The Cretaceous–Palaeogene iridium anomaly
24. Bottaccione Gorge, Gubbio
25. The end-Triassic mass extinction
26. Evidence
27. Supports the stage and period boundary ages used throughout this pack, including the Cambrian base at 538.8 ± 0.2 Ma on recent editions against 541.0 ± 1.0 Ma on earlier ones. V55 verification basis: this session had no network access to any source — WebFetch was egress-blocked and the WebSearch budget was exhausted — so the cited work was not retrieved and its pagination was not re-checked. No chart edition was opened, so the boundary figures are quoted from standing knowledge of the chart rather than read from it, and the edition in which the Cambrian base changed is not identified.
28. Supports the general Precambrian narrative used here: stromatolite biogenicity reasoning, banded iron formation requirements, endosymbiotic origin of organelles and the framing of mass extinction as a measurement problem. Published in 2003, so it predates the 2016, 2018 and 2024 results also cited in this pack. V55 verification basis: this session had no network access to any source — WebFetch was egress-blocked and the WebSearch budget was exhausted — so the cited work was not retrieved and its pagination was not re-checked.