Event |
Time |
“Lucy” (Australopithecus afarensis) |
4 mya |
Camel |
35 mya |
Grass |
55 mya |
Cenozoic Era begins |
65 mya |
Tyrannosaurus |
65 mya |
Ants |
100 mya |
First flowering plants |
125 mya |
Archaeopteryx |
140 mya |
Stegosaurus |
160 mya |
First mammal |
240 mya |
Mesozoic era begins |
320 mya |
Pangaea forms |
260 mya |
Earthworms |
300 mya |
Cockroaches |
330 mya |
Ferns |
370 mya |
Sharks |
400 mya |
Spiders |
450 mya |
Trilobites |
520 mya |
Jellyfish |
545 mya |
Paleozoic era begins |
545 mya |
Green algae |
1 bya |
Bacteria |
3 bya |
Precambrian era begins |
4.6 bya |
Figure 1.
Events on the geological timeline
* Note (mya= million
years ago, bya= billion years ago). These dates are
approximations and will vary depending on sources consulted.