ERA
|
PERIOD
|
AGE
(of start)
|
Cenozoic
|
|
1.6 my
|
|
65 my
|
Mesozoic
|
|
140 my
|
|
205 my
|
|
250 my
|
Paleozoic
|
|
290 my
|
|
355 my
|
|
410 my
|
|
438 my
|
|
510 my
|
|
540 my
|
|
Jurassic 205 - 140 million years
ago
Life
Dominant life includes:
Dinosaurs, mammals, gymnosperm and fern
forests
First birds
With Pangea beginning to break apart, the
climate became less dry with rain and seasonal snow. Ice
formed at the poles.
During the late Jurassic, Pangea began to
break apart, allowing land far from water to get rain needed
for growth and food.
The main rock types in PA is diabase.
|