Upper Triassic

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The Late Triassic
Coelophysis, one of the first dinosaurs, appeared in the Upper Triassic.

The Upper Triassic is the last epoch in the Triassic. It began 237 million years ago, and ended at 201.3 million years ago. Before it was the Middle Triassic It is followed by the Lower Jurassic.

The other two epochs of the Triassic were the Lower and Middle Triassic.

Many early dinosaur species appeared for the first time during the Upper Triassic, including Plateosaurus, Coelophysis, and Eoraptor. Pterosaurs were common in the air, and Ichthyosaurs dominated the seas.

At the end of the Upper Triassic some event or events caused the extinction of many animal species worldwide. Known as the end–Triassic extinction event, it was similar to the more famous event that lead to the extinction of the dinosaurs, except no one knows for sure what caused the event.

Carnian pluvial event[change | edit source]

Although the Triassic was, in general, a dry period with inland areas often deserts, the Upper Triassis saw a big change.

The Carnian Pluvial Event (CPE) was a major global climate change and biotic turnover (many extinctions) early in the Upper Triassic, ~ 230 million years ago.[1][2] Shifts in carbon and oxygen isotopes suggest a global warming.[3][4][5]

Major changes in organisms responsible for calcium carbonate production occurred during the CPE.[6][7][8] Carbonate sedimentation stopped in deep water settings of Southern Italy.[9] High extinction rates occurred among ammonoids, conodonts, bryozoa and crinoids.[1] Major evolutionary innovations followed the CPE, as the first occurrence of dinosaurs, calcareous nannofossils and scleractinian corals.[2][3]

References[change | edit source]

  1. 1.0 1.1 Simms M.J.; Ruffell A.H. (1989). "Synchroneity of climatic change and extinctions in the late Triassic". Geology 17: 265–268.
  2. 2.0 2.1 Furin S. et al (2006). "High-precision U-Pb zircon age from the Triassic of Italy: implications for the Triassic time scale and the Carnian origin of calcareous nannoplankton and dinosaurs". Geology 34 (12): 1009–1012.
  3. 3.0 3.1 Dal Corso J. et al (2012). "Discovery of a major negative δ13C spike in the Carnian (Late Triassic) linked to the eruption of Wrangellia flood basalts". Geology 40 (1): 79–82.
  4. Hornung T. et al (2007). "Multistratigraphic constrains in the NW Tethyan "Carnina Crisis"". New Mexico Museum of Natural History and Science Bulletin 41: 59–67.
  5. Rigo M.; Joachimski M.M. (2010). "Palaeoecology of late Triassic conodonts: Constraints from oxygen isotopes in biogenic apatite". Acta Palaeontologica Polonica 55 (3): 471–478.
  6. Keim L.; Schlager W. (2001). "Quantitative compositional analysis of a Triassic carbonate platform (Southern Alps, Italy)". Sedimentary Geology 139: 261–283.
  7. Hornung T.; Krystin L.; Brandner R. (2007). "A Tethys-wide mid-Carnian (Upper Triassic) carbonate productivity crisis: Evidence for the Alpine Reingraben Event from Spiti (Indian Himalaya)?". Journal of Asian Earth Sciences 30: 285–302.
  8. Stefani M.; Furin S. & Gianolla P. (2010). "The changing climate framework and depositional dynamics of Triassic carbonate platforms from the Dolomites". Palaeogeography, Palaeoclimatology, Palaeoecology 290: 43–57.
  9. Rigo M. et al (200). "A rise in the Carbonate Compensation Depth of western Tethys in the Carnian: deep-water evidence for the Carnian Pluvial Event". Palaeogeography, Palaeoclimatology, Palaeoecology 246: 188–205.