I always like to keep a context for this sort of stuff. Here's my growing list:
giant impact that formed the moon (4.5bya)
great oxidation event (2.4-2.0bya)
multicellular life (1.5bya-600mya)
trilobytes appear (521mya)
landplants (470mya)
first land animal (428mya)
pangea forms (335mya)
pangea breaks apart (200mya)
angiosperms (275mya)
trilobytes disappear (252mya)
ginkgo (200mya)
flowering plants become abundant (100mya)
antartica was a rainforest (90mya)
dinosaurs died (65mya)
primates (55mya)
azolla event (49-48mya)
pantherlike cats (10.8mya)
first humans (5mya)
megalodons go extinct (2.6mya)
modern humans (300k years ago)
yellowstone's last eruption (70k years ago)
humans reach turtle island (30-20k years ago)
african humid period, green sahara (14.5-5k years ago)
beringia land bridge gets inundated (11k years ago)
saber tooth tigers go extinct (10k years ago)
horses go extinct in north america (9k years ago)
shift to wetter climate makes Amazonia transition from grasslands to jungle (2k years ago)
