A Great Adaptive Radiation of Mammals Began About ____ Million

Question

A great adaptive radiation of mammals began about ____ million years ago.  
A) 25
B) 65
C) 95
D) 125
E) 165

Accepted Answer

The great adaptive radiation of mammals began about 65 million years ago, following the extinction of non-avian dinosaurs at the end of the Cretaceous period. This allowed for the ecological niches previously occupied by dinosaurs to be filled by mammals, resulting in the diversification and evolution of many new mammalian groups.