more than 90% Many of those extinctions most happened at the same time On the causes of mass extinctions more than 90% typically around 6-7ºC reviewed the evidence On the causes of mass extinctions On the causes of mass extinctions more than 90% several times Many of those extinctions Many of those extinctions On the causes of mass extinctions Many of those extinctions more than 90% On the causes of mass extinctions reviewed the evidence On the causes of mass extinctions fairly consistent Bond and Grasby most happened at the same time most happened at the same time Bond and Grasby fairly consistent several times typically around 6-7ºC more than 90% most happened at the same time more than 90% On the causes of mass extinctions On the causes of mass extinctions several times more than 90%