Second Gunman in Death of the Dinosaurs
A cunning study of geology, shells and ancient magnetism offers clues to a long-ago extinction
http://science.time.com/2012/09/11/second-gunman-in-death-of-the-dinosaurs/?hpt=hp_t3
It seems that the great dinosaur killer asteroid wasn’t such a great dinosaur killer after all. More like it gave the coup de grace to an ecosystem already heavily damaged by a string of environmental catastrophes. I have read several discussions in the past where, while the impact was certainly huge (monumental by human standards), it shouldn’t have been enough to cause such a global extinction. There should have been more than enough resilience in the ecosystem to absorb the impact (no pun intended) and while it is likely there would have been a lot of species vanish, the slate wouldn’t have been wiped so clean that mammals would have been able to take over. However, as this (and other) research is showing, it seems that the Earth’s ecosystem was already reeling from a series of ‘self inflicted’ wounds and that the asteroid impact was just the last little bit to push every one over the edge.
