Early Jurassic, e.g (5)

I believe the answer is:

epoch

(Other definitions for epoch that I've seen before include "Geological time period" , "Period, era" , "Period of notable events" , "Distinctive period of time" , "A particular period of history" .)

I've seen this clue in The New York Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.