Ordovician-Silurian Extinction (about 443 million years ago): Around 85% of species went extinct, likely due to a combination of a drop in sea levels and glaciation, followed by rising sea levels ...

The end-Ordovician, or Ordovician-Silurian, extinction saw the demise of approximately 85 percent of the earth’s species. The late Devonian extinction was slightly less severe, accounting for ...

The Ediacaran Period’s odd animals never got their chance to shine, thanks to a precarious drop in oxygen levels about 550 million years ago that triggered the first-ever extinction event. At least, ...

A significant shift in Earth’s history, the Ordovician-Silurian extinction event, took place 444 million years ago. This era grasped my attention as it witnessed the extinction of 86% of Earth ...

They precisely determined the absolute ages of the Katian–Hirnantian boundary (442.65+0.17/−0.23 Ma) and the Ordovician–Silurian boundary (442.33+0.34/−0.33 Ma), constraining the duration ...

[3] Macroevolutionary Transition in Crinoids Following the Late Ordovician Extinction Event (Ordovician to Early Silurian). Palaeogeography Palaeoclimatology Palaeoecology (2012).

A significant shift in Earth’s history, the Ordovician-Silurian extinction event, took place 444 million years ago. This era grasped my attention as it witnessed the extinction of 86% of Earth ...