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Precambrian Period 4600 MA
10: The presence of stromatolites indicates that shallow seas covered much of the Earth during intervals in this period
11:Nearly half of the valuable mineral deposits in the world occur in the rocks of this period. -
Period: to
M. Turrisi P8
Geological Timescale -
Cambrian 542 MA
22: Trilobites appear.
23: Shelled Brachiopods appear. -
Ordovician 488 MA
30: Colonies of tiny invertebrates called graptolites flourished and vertebrates appear, fish did not have jaws or teeth and their bodies were covered in bony plates.
1: There was very little plant life during this period. -
Silurian 444 MA
24: Eurypterids, sea stars and coral become more common
33: vascular land plants and animals, such as scorpians beginning to evolve on land. -
Devonian 416 MA
21: Early reptiles resembling large lizards appear.
37: Age of fishes, fish that can breathe out of the water and spend time on land form. -
Carboniferous 359-318 MA
2: Swamps and forests cover the land
15: Coal deposits form. -
Permian 299 MA
8: Appalachian Mountains are created because of the collision of tectonic plates and savannas form.
38: Environmental changes causes mass extinction of sea invertebrates (Trilobites and Eurypterids) as the seas retreat. -
Triassic 251 MA
16: Welcome to the world of the Dinosaur. Enter the squirrel sized dinosaur & the first forest dwelling mammals appear.
34: Ichthyosaurs are living in the ocean, new invertebrates called ammonite develop. -
Jurassic 200 MA
3: Fly reptiles called pterosaurs are in the air now.
13: Whoa those dino's are getting big and dominate the land- Lizard hipped and bird-hipped appear- carnivores and herbivores have arrived. -
Cretaceous 146 MA
5: First flowering plant- angiosperm
35: Impact hypothesis- dinosaur extinction. -
Paleocene 65.5 MA
29: Small rodents evolve.
12: First primates evolve. -
Eocene 55.8 MA
17: Flying squirrels, whales and bats appear.
25: Worldwide temp. drops 4 degrees Celsius (39.2 degrees F.) -
Oligocene 33.9 MA
6: Himalayas develop due to uplifting caused by the Indian subcontinent and Eurasian continents colliding.
27: Many early mammals become extinct, clams and snails flourish. -
Miocene 23 MA
32: Antarctic Ice caps begin to form.
36: Mediterranean dries up and refills due tectonic forces dropping sea levels. -
Pliocene 5.3 MA
26: First modern horses appear.
18: Various species migrated between continents due to land bridges. -
Pleistocene 1.8 MA
9: Homo sapiens appeared and are hunters.
20: Species that did not survive extreme cold moved to warmer areas or became extinct (Dire wolf and Giant ground sloth). -
Holocene .0115 MA
19: The last glacial period ended sea levels rose, great lakes appeared.
28: Modern human developed agriculture and made tools of bronze and iron. -
Anthropocene Current Day
7: Some scientists believe humans kind has caused mass extinctions of plants and animal species, polluted the oceans, and altered the atmosphere.
14: There is argument to when the Epoch began, some scientists think it began with the industrial age in the late 1800's, others think it began in the atomic age in the 1950's
