PBS Eons has a new episode. This one is about ocean extinctions during the Silurian Period. It wasn't the quiet time that was once thought.
What graptolites tell us is a story of incredible changes in the ocean, of periods where the oceans became poisonous and suffocating before eventually clearing up again. They unlock extinctions and recoveries that scientists didn't see. And, most of all, they show us how unpredictable the Silurian period really could be.
