The second-largest mass extinction in Earth’s history took place in a period of stresses from non-sulfidic anoxia in shelf areas, together with glacioeustatic sea-level change and climatic cooling.
A new study of seafloor sediments finds that the temperature record in the early Paleozoic corresponds to significant shifts in the diversity of life on Earth.
Cyclical changes in Earth’s orbit helped to preserve rare fossils in Morocco.
Dead algae sinking to the ocean floor may have sequestered carbon 445 million years ago, triggering the glaciation that accompanied the Late Ordovician mass extinction.
Abnormally high levels of mercury in Ordovician rocks may imply that a huge surge of volcanism took place at a time when much of the planet’s ocean life vanished.