In place of oxygen, the ocean was full of hydrogen sulfide, which the researchers believe may have caused the organism to ...

a series of mass extinction events that occurred 372 million years ago, and the Ordovician, which occurred 445 million years ago and was the first of the big five mass extinction events in our ...

Instead, the team hypothesized a stellar explosion may have been a potential factor in the Late Devonian extinction event 372 million years ago and one at the end of the Late Ordovician 445 ...

They believe a supernova explosion close to Earth could be to blame for both the late Devonian and Ordovician extinction events, which occurred 372 and 445 million years ago respectively.

Instead, the team hypothesized a stellar explosion may have been a potential factor in the Late Devonian extinction event 372 million years ago and one at the end of the Late Ordovician 445 million ...