Cenozoic
Cenozoic era
Age of Mammals

Woodlands covered the state during the early part of the Cenozoic era.

During the early Cenozoic era the state was still mostly covered in seawater, but local sea levels began to rise and fall.

Sea levels rose and fell throughout the ensuing Cenozoic era.

Some fossil snakes from the Cenozoic era are also known.

Likewise, little is known about the early to middle Cenozoic era.

Most of Arizona was dry land during the Cenozoic era.

Delaware was still mostly covered by sea water through the Cenozoic era.

The sea gave way to a complex of lakes during the Cenozoic era.

Local sea levels rose and fell during the ensuing Cenozoic era.

During the later part of the Cenozoic era, the local climate cooled.