This hypothesis about the end Permian mass extinction is also quite scary: http://burro.case.edu/Academics/USNA229/impactfromthedeep.pdf http://burro.case.edu/

This hypothesis about the end Permian mass extinction is also quite scary: http://burro.case.edu/Academics/USNA229/impactfromthedeep.pdf http://burro.case.edu/Academics/USNA229/impactfromthedeep.pd...