1. The Proterozoic Eon
Page 33 of INB

2. Essential Question:
How did the type of organisms on Earth change during the Proterozoic Eon?

3. The Proterozoic Eon Proterozoic eon: 2,500 – 542 mya
During the Proterozoic eon, oxygen was added to the atmosphere.
3% 20%
Catastrophe: from Greek katastrephein, means “to overturn”

4. The Proterozoic Eon
The Snowball Earth hypothesis states that Earth was completely covered with ice at the end of the Proterozoic eon.

5. The Proterozoic Eon
Scientist hypothesize that the supercontinent Rodinia formed during the Proterozoic eon.
Rodinia might have formed as separate continents collided and stuck together.
Shallow waters were a life rich environment.

6. The Proterozoic Eon -Soft bodies make evidence hard to find.
-The first multicellular organisms evolved in the oceans at the end of the Proterozoic eon.
-Soft bodies make evidence hard to find.

7. Page 32
Questions 4 & 5