Prehistoric Period Lasted Around 3.4 Million Years
This page is the CodyCross answer for the clue below from Small World, Group 682, Puzzle 4 (Breakfast Cereal).
Question is: Prehistoric Period Lasted Around 3.4 Million Years
and the answer is: STONEAGE
Word Meaning:
STONE AGE — Alternative letter-case form of Stone Age.
Definitions from Wiktionary.