Mammals Were on the Rise Before Dinosaurs Checked Out

A recent study published in the journal Nature finds mammals began to diversify 30 million years before dinosaurs went extinct. And the number of mammal species continued to rise steadily through the extinction of the dinosaurs.

The researchers examined molecular samples representing nearly all extant (still living today) mammal species. This data indicates mammals didn't get a bump from the death of dinosaurs, but were already well on their way to biological success.

While not proven by this research, the early rise of mammals correlates with the rise of flowering plants (including grasses, flowers, and most modern trees), and a global drop in temperatures.