1-2: Paleolithic Era
3-4: Neolithic Era
5-6: Bronze Age
7-8: Iron Age
9-10: Classical Era
11-12: Medieval Era
13-14: -Renaissance
15-16: Age of Exploration
17-20: Enlightenment
21-24: Industrial Revolution
25-26: Modern Era
27-28: Contemporary Era
29: We destroy ourselves
(the end of the story would be very unlikely, I know)
30: New Species a few million years later
34: They experience their own Paleolithic-Iron age eras faster than we did
38: They skip through lots of ages which we experienced
46: they experience their own contemporary era
50: They branch into the galaxy
58: over billions of years they colonize the milkyway
70: Andromeda collides with milkyway, revealing that this species, is too, fragile.
74: they dwindle down to a singular solar system
78: over trillions of years, the evidence that they had existed dwindles away to nothing.