Geological Sciences | Science Communication
Severity: TBD Cause: Fossil fuel combustion Climate: Rapid climate change, sea level change, ocean acidification, ocean anoxia, ozone destruction Aftermath: ?? Mass extinction aren’t just something of the past; it’s commonly accepted that we’re in one right now. While the Anthropocene isn’t yet an official epoch, there is mounting evidence to suggest that human activity has caused such a… Continue reading Mass Extinction Monday | BONUS – THE ANTHROPOCENE (present day)
[Also formerly known as the Cretaceous-Tertiary (K-T) and now as the Cretaceous-Paleogene (K-Pg) extinction] Severity: 5th worst Cause: Meteorite impact released CO2 from carbonates Climate: Cold (SO2) then warm (CO2) Aftermath: Mammals arise Even though the End-Cretaceous is the least severe of all the mass extinctions, with 62% of species and 11% of families wiped… Continue reading Mass Extinction Monday | END-CRETACEOUS (65 Ma)
Severity: 4th worst Cause: Central Atlantic Flood Basalts, meteorite impact (?) Climate: Hot; Pangaea mostly desert Aftermath: Dinosaurs diversify Only 50 My after the End-Permian extinction, 65% of species and 12% of families were wiped out during the End-Triassic extinction. The exact cause of this extinction is still not very well constrained. It could possibly… Continue reading Mass Extinction Monday | END-TRIASSIC (200 Ma)
Severity: 1st worst Cause: Eruption of Siberian Traps Climate: Cold to extremely warm; ocean acidification and anoxia, ozone destruction Aftermath: Permanent ecosystem reorganization; low O2 for >106 years There’s good reason why the End-Permian extinction is referred to as “The Great Dying”; 95% of all species, 53% of all marine families, 84% of marine genera,… Continue reading Mass Extinction Monday | END-PERMIAN (250 Ma) – “The Great Dying”
Severity: 3rd worst Cause: Still unclear, changes in sea level and ocean anoxia (?) Climate: Abrupt cooling Aftermath: Marine filter feeders diversify Rather similar to the End-Ordovician extinction, warm-water marine invertebrates were the hardest hit during the Late Devonian extinction. 22% of known marine families and 57% of marine genera were wiped out during a global cooling event. Gondwana glaciations were… Continue reading Mass Extinction Monday | LATE DEVONIAN (365 Ma)
Severity: 2nd worst Cause: Some type of C cycle disturbance, not well constrained Climate: Abrupt ice age followed by rapid warming Aftermath: Cambrian organisms (e.g. trilobites) decimated During the End-Ordovician mass extinction, 25% of known marine families and 60% of marine genera were wiped out. Warm-water invertebrates were the hardest hit, as the event was… Continue reading Mass Extinction Monday | END-ORDOVICIAN (440 Ma)
Starting a new feature here! Every Monday, they’ll be a little overview of each of the five big mass extinctions, To start off, we’re going to do a bit of a general overview. Around 99% of all species that have ever lived on Earth are extinct.1 However, this extinction rate is far from constant, as organisms… Continue reading Mass Extinction Monday!
Emily Zawacki, Ph.D. 