Culprit for Mass Extinction 445 Million Years Ago? Global Warming - The New York Times
https://www.nytimes.com/2020/06/10/science/global-warming-ordovician-extinction.html
Planetary Scientists Discover That Mars Underwent a Great Oxygenation Event Billions of Years Ago
https://scitechdaily.com/planetary-scientists-discover-that-mars-underwent-a-great-oxygenation-event-billions-of-years-ago/
Rise of oxygen on Earth: Initial estimates off by 100 million years | EurekAlert! Science News
https://www.eurekalert.org/pub_releases/2021-04/uoc--roo040221.php