Solved UPSC CDS/OTA Question
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Q · Geological Time ScaleMedium · 45s
The earliest known fossils of life (stromatolites) are found in which Eon?
TopicGeological Time Scale
Question Typemultiple choice
DifficultyMedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
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Explanation:Earliest life (cyanobacteria, stromatolites) date back to the Archean Eon (~3.5 billion years ago).
Final Answer: Option A - Archean