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  2. Late Ordovician mass extinction - Wikipedia

    en.wikipedia.org/.../Late_Ordovician_mass_extinction

    An illustration depicting Cameroceras shells sticking out of the mud as a result of draining seaways during the Ordovician-Silurian Extinction event. The cause of the glaciation is heavily debated. The late Ordovician glaciation was preceded by a fall in atmospheric carbon dioxide (from 7,000 ppm to 4,400 ppm).

  3. Silurian - Wikipedia

    en.wikipedia.org/wiki/Silurian

    The Silurian period has been viewed by some palaeontologists as an extended recovery interval following the Late Ordovician mass extinction (LOME), which interrupted the cascading increase in biodiversity that had continuously gone on throughout the Cambrian and most of the Ordovician. [36] The Silurian was the first period to see megafossils ...

  4. Hirnantian - Wikipedia

    en.wikipedia.org/wiki/Hirnantian

    Most scientists believe that this climatic oscillation caused the major extinction event that took place during this time. In fact, the Hirnantian (also known as the End Ordovician and the Ordovician-Silurian) mass extinction event represents the second largest such event in geologic history. Approximately 85% of marine (sea-dwelling) species died.

  5. Llandovery Epoch - Wikipedia

    en.wikipedia.org/wiki/Llandovery_Epoch

    In the geological timescale, the Llandovery Epoch (from 443.8 ± 1.5 million years ago to 433.4 ± 0.8 million years ago) occurred at the beginning of the Silurian Period. . The Llandoverian Epoch follows the massive Ordovician-Silurian extinction events, which led to a large decrease in biodiversity and an opening up of ecosyste

  6. Late Ordovician - Wikipedia

    en.wikipedia.org/wiki/Late_Ordovician

    Brachiopods, bryozoans and echinoderms were also heavily affected, and the endocerid cephalopods died out completely, except for possible rare Silurian forms. The Ordovician-Silurian Extinction Events may have been caused by an ice age that occurred at the end of the Ordovician period as the end of the Late Ordovician was one of the coldest ...

  7. List of periods and events in climate history - Wikipedia

    en.wikipedia.org/wiki/List_of_periods_and_events...

    Dresbachian extinction event 486.85: Cambrian–Ordovician extinction event: 450–440: OrdovicianSilurian extinction event, in two bursts, after cooling perhaps caused by tectonic plate movement 450: Andean-Saharan glaciation: 360–260: Karoo Ice Age: 305: Cooler climate causes Carboniferous rainforest collapse: 251.9: Permian–Triassic ...

  8. Scientists Discovered a Surprise 6th Mass Extinction, Which ...

    www.aol.com/scientists-discovered-surprise-6th...

    Researchers have gone back in time to find an extinction event that predates all other known events of their kind. Scientists Discovered a Surprise 6th Mass Extinction, Which Came Before the Big 5 ...

  9. List of extinction events - Wikipedia

    en.wikipedia.org/wiki/List_of_extinction_events

    Ordovician: Late Ordovician mass extinction: 445-444 Ma Global cooling and sea level drop, and/or global warming related to volcanism and anoxia [43] Cambrian: Cambrian–Ordovician extinction event: 488 Ma: Kalkarindji Large Igneous Province? [44] Dresbachian extinction event: 502 Ma: End-Botomian extinction event: 517 Ma: Precambrian: End ...