4 ms·
https://en.wikipedia.org/wiki/Ordovician%E2%80%93Silurian_extinction_events#Gamma_ray_burst_hypothesis https://en.wikipedia.org/wiki/Ordovician%E2%80%93Silurian
by empath75 9y ago
https://en.wikipedia.org/wiki/Ordovician%E2%80%93Silurian_extinction_events#Gamma_ray_burst_hypothesis https://en.wikipedia.org/wiki/Ordovician%E2%80%93Silurian_ex...