Geological Sciences | Science Communication
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!
Ammonite (Placenticeras intercalare) Bearpaw Formation, Lethbridge, Alberta, Canada 75 million years old American Museum of Natural History - NYC Image by author
The Jurassic (early Mesozoic) is known as the ‘Age of the Ammonites,’ as they were the original index fossils used by William Smith. Along with dinosaurs, corals, brachiopods, and molluscs, they were among the hardest hit species during the K-T extinction 65 Ma. Image by author
Here’s a few highlights from the history of the Earth and life during the Cenozoic Era, the third of the Phanerozoic, which is the fourth Eon in Earth’s history. These events are mainly focused on North America, and the dates of Periods and Epochs are partially rounded. CENOZOIC (CZ) [65 Ma – on] PALEOGENE (PE)… Continue reading Highlights of the Phanerozoic: Part 3 – Cenozoic [65 Ma – on]
Here’s a few highlights from the history of the Earth and life during the Mesozoic Era, the second Era of the Phanerozoic, which is the fourth Eon in Earth’s history. These events are mainly focusing on North America, and the dates for Periods and Epochs have been partially rounded. MESOZOIC (MZ) [251 – 65 Ma]… Continue reading Highlights of the Phanerozoic: Part 2 – Mesozoic [251 – 65 Ma]
Here’s a few highlights from the history of the Earth and life during the Paleozoic Era, the first Era of the Phanerozoic, which is the fourth Eon in Earth’s history. These events are mainly focusing on North America, and the dates of Periods and Epochs are partially rounded. PALEOZOIC ERA [542 - 251 Ma] CAMBRIAN (Є)… Continue reading Highlights of the Phanerozoic: Part 1 – Paleozoic [542 – 251 Ma]
Denver Museum of Nature and Science, Prehistoric Journey
Emily Zawacki, Ph.D. 