Geologic Time Scales
Dating from 360-286mya, the Carboniferous Period began after the second major extinction of life on Earth. With the Carboniferous, insects evolved wings, and certain amphibians evolved amniotic eggs, allowing for the evolution of reptiles. Temperatures became milder, marking a decline in the number of ferns and large insects.
The Carboniferous Period can be further divided into two epochs, the
Mississippian, or Lower Carboniferous, and the Pennsylvanian, or Upper
Carboniferous. The Mississippian fossils are found in strata of limestone,
while the Pennsylvanian fossils are found in coal-bearing layers of rocks.
The Mississippian Epoch dates 360-325mya. The Pennsylvania Epoch dates