What is the oldest era of Earth?

Related questions

1. What are the 3 eons?
2. What is the current epoch?
3. How many aeons are there?
4. What EON are we currently in?
5. Is Eoin Irish for John?
6. What is AEON Japan?
7. Did Vikings invade Scotland?
8. What do you mean by Eon?
9. What epoch are we in now?
10. What is the oldest era?

Tags

1. #years
2. #cambrian
3. #devonian
4. #periods
5. #subdivided
6. #carboniferous
7. #silurian
8. #youngest
9. #million
10. #ordovician
11. #permian
12. #paleozoic
13. #geologic
14. #oldest
15. #spanned
16. #roughly