Name:

Earth History in 24 hours

  1. Your assignment is to map the Earth's history into a 24 hour period. To do this the time in years of each Earth history event must be converted to hours. Complete the list below. The first conversion is given.
  2. On the back of this paper draw a large circle with a compass or template. Divide it into 24 equal slices. This creates a 24 hour clock face. Mark the events on your 24 hour clock. Provide annotation as appropriate (or possible!). Neatness counts.
  1.       0 hrs           4600 mya     estimated age of Earth
  2.     4.2 hrs         3800 mya     age of oldest rock
  3. _________       3500 mya     first bacteria (1st fossils)
  4. _________       600 mya       first jellyfish
  5. _________       570 mya       Gondwana forms
  6. _________       543 mya       first trilobites
  7. _________       540 mya       land plants appear
  8. _________       515 mya       first vertebrates
  9. _________       480 mya       Taconic orogeny (Appalachian Mtns.)
  10. _________       475 mya       first fish
  11. _________       420 mya       land animals appear
  12. _________       400 mya       sharks appear
  13. _________       400 mya       spiders appear
  14. _________       370 mya       ferns appear
  15. _________       340 mya       first seed plants
  16. _________       310 mya       first reptiles
  17. _________       300 mya       first winged insects
  18. _________       300 mya       first earthworms
  19. _________       250 mya       Pangaea forms
  20. _________       250 mya       trilobites go extinct (greatest mass extinction)
  21. _________       245 mya       first dinosaurs
  22. _________       225 mya       first mammals
  23. _________       200 mya       birds appear
  24. _________       160 mya       Stegosaurus
  25. _________       125 mya       first flowering plants
  26. _________       100 mya       ants
  27. _________         70 mya       Laramide orogeny (Rocky Mtns.)
  28. _________         65 mya       Tyrannosaurus
  29. _________         65 mya       dinosaurs become extinct
  30. _________         60 mya       first primates
  31. _________         55 mya       rabbits appear
  32. _________         36 mya       Cascade orogeny
  33. _________         20 mya       grasses appear
  34. _________           4 mya       human ancestors appear
  35.     24.0 hrs           12 kya       last continental glaciation