Diversity between organisms in the Cenozoic era is infinite.

Many nocturnal animals and only certain organisms were able to adapt to the changes in climate.

Also small reptiles were able to adapt to the warmer  areas of the earth.

Organisms and how they survived

Types of organisms that existed and exist today:

-Fish

-Insects

-Mammals 

-Humans (also mammals)

-Birds

-Reptiles

-Plants