Impact events, proposed as causes of mass extinction, are when the planet is struck by a comet or meteor large enough to create a huge shockwave felt around the globe. Widespread dust and debris rain down, disrupting the climate and causing extinction on a global, rather than local, scale. The demise of the dinosaurs at the end of the Cretaceous has been linked to an impact that left a crater in the seabed off the Yucatan peninsula of Mexico. Impacts have also been blamed for other mass extinctions, but the timing and links between cause and effect for these is still debated by scientists.

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