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Precambrian time 4,600 MA
EVENT 1 There is ery little plant life during this period. EVENT 10 The presence of stromatolites indicates that shallow seas covered much of Earth during intervals in this period -
Period: to
N Asensio 3
Geological Timescale -
Cambrian 452 MA
EVENT 22 Trilobites appear. EVENT 23 Shelled brachiopods appear -
Ordovician 488 MA
EVENT 30 Colonies of tiny invertebrates call graptolites flourished and vertebrates appear, Fish did not have jaws or teeth and their bodies were covered with bony plates -
Silurian 444 MA
EVENT 24 Eurypterids (sea scorpians), sea stars and corral become more common. EVENT 33 Vascular land plants and animals, such as scorpions begin to evolve on land -
Devonian 416 MA
EVENT 32 Huge plants begin to develop, early amphibians form. EVENT 37 Age of fishes, fish that breathe out of water and spend time on land form -
Carboniferous Mississippian period 359 MA
EVENT 2 Swamps and forests cover the land. EVENT 13 Coal deposits form -
Carboniferous Pennsylvanian Period 318 MA
EVENT 4 Giant cockroaches appear. EVENT 21 Early reptiles resembling large lizards appear -
Permian 299 MA
EVENT 8 Appalachian Mountains are created because of the collision of tectonic plates and savannas form. EVENT 38 Environmental changes cause mass extinction of sea invertebrates (trilobites & eurypterids) as sea retreats -
Triassic 251 MA
EVENT 16 Welcome to the world of the Dinosaur! Enter the squirrel sized dinosaur & the first forest dwelling mammals appear. EVENT 34 Icthyosaurs are living in the ocean, new invertebrates call ammonite develop -
Jurrasic 200 MA
EVENT 3 Flying reptiles called pterosaurs are in the air now. EVENT 16 Whoa those dinos are getting big & dominate the land - Lizard-hipped and bird-hipped appear - carnivores and herbivores have arrived -
Cretaceous 146 MA
EVENT 5 First flowering plants appear - angiosperm. EVENT 35 Impact hypothesis - dinosaur mass extinction -
Tertiary Palocene 65.5 MA
EVENT 29 Small rodents evolve. EVENT 12 First primates evolve -
Tertiary Eocene 55.8 MA
EVENT 17 Flying squirrels, whales, and bats appear. EVENT 25 Worldwide temperatures drop about 4 degrees celcius -
Tertiary oligocene 33.9 MA
EVENT 6 Himalayas develop due to uplifting cause by the indian subcontinent and Eurasian continents colliding. EVENT 27 Many early mammal become extinct, clams and snails flourish -
Tertiary Miocene 23.0 MA
EVENT 32 Antarctica ice caps begin to form. Mediterranean Sea dries up and refills several times due to tectonic forces dropping sea levels -
Tertiary Pliocene 5.3 MA
EVENT 26 First modern horses appear. EVENT 18 Variuos species migrated between continents using land bridges -
Quaternary Pleistocene 1.8 MA
EVENT 9 Homosapien (modern humans) appeared & are hunters. EVENT 20 Species that did not evolve to survive extreme cold moves to warmer climate areas or became extinct (dire wolf & giant sloth) -
Quaternatary Holocene 0.0115 MA
EVENT 19 The last glacial period ended and sea levels rose, Great Lakes formed. EVENT 28 Modern human developed agriculture and used tools made of bronze and iron -
Quaternary Anthropocene Present day
EVENT 13 Scientists arent sure when this epoch began, some say in the 1800s some say in the 1950s. EVENT 7 Scientist believe humans has caused extinction of plants and animals, polluted the oceans and altered the atmosphere
