Ries Basin, a mere 15 million years ago I think. Next time one of those happens it may be with no warning, despite current efforts.
We sit on our perch precariously. When I visted McDonadl's observatory, the visitors' center showed a film that made a great impression. The CGI showed a tiny earth moving through the fiery sea of the suns extreme atmosphere, protected from extinction only by the earth magnetic field. Having seen this I can hardly take serious the global warning crowd. A slight blip in that magnetic field could cause more change than all the works of man. But ditto with some monstrous volcanic event(s). Puny, puny man. Yet....