The Extinction of what group of animal is caused by the global climate?

Climate change has caused mass extinctions of species throughout geologic time, dating back millions of years. The earth goes through cyclic temp changes constantly, and species adapt, evolve, or simply die out. The current period of "climate change" has not been severe enough yet to cause any major fauna extinctions as of this time, and chances are good that it may not, as the warming claims may have been exaggerated.