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Precambrian (4600)
1 There is very little plant life during this period. 11 Nearly half of the valuable mineral deposits in the world occur in the rocks of this period. -
Period: to
J Pereira - 1 Period
Geological Timescale -
Cambrian (542)
10 The presence of stromatolites indicates that shallow seas covered much of Earth during intervals in this period. 22 Trilobites appear. -
Ordovician (488)
23 Shelled brachiopods appear. 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)
24 Eurypterids (sea scorpions), sea stars and coral become more common. 33 Vascular land plants and animals, such as scorpions begin to evolve on land -
Devonian (416)
31 Huge plants begin to develop, early amphibians form. 37 Age of Fishes, fish that can breath out of the water and spend time on land form. -
Mississippian Period (359)
2 Swamps and forests cover the land. 34 Ichthyosaurs are living in the ocean, new invertebrates call ammonite develop. -
Pennsylvanian Period (318)
4 Giant cockroaches appear. 15 Coal deposits form. -
Permian (299)
21 Early reptiles resembling large lizards appear. 38 Environmental change causes the mass extinction of sea invertebrates (trilobites & eurypterids) as the seas retreated. -
Triassic (251)
16 Welcome to the world of the Dinosaur! Enter the squirrel-sized dinosaur & the first forest dwelling mammals appear. 29 Small rodents evolve. -
Jurassic (200)
3 Flying reptiles called pterosaurs are in the air now. 13 Whoa those dinos are getting big & dominate the land - Lizard - hipped and bird - hipped appear - carnivores and herbivores have arrived. -
Cretaceous (146)
5 First flowering plants appear-angiosperm. 35 Impact hypothesis- dinosaur mass extinction. -
Paleocene (65.5)
6 Himalayas develop due to uplifting caused by the Indian subcontinent and the Eurasian continents colliding. 12 First primates evolve. -
Eocene (55.8)
17 Flying squirrels, whales and bats appear. 26 First modern horses appear. -
Oligocene (33.9)
27 Many early mammal become extinct, clams and snails flourish. 32 Antarctic ice caps begin to form. -
Miocene (23.0)
8 Appalachian Mountains are created because of the collision of tectonic plates & savannahs form.18 Various species migrated between continents across land bridges. -
Pliocene (5.3)
20 Species that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (dire wolf & giant ground sloth). 36 The Mediterranean Sea dries up and refills several times due to tectonic forces and dropping sea levels. -
Pleistocene (1.8)
9 Homosapien (modern humans) appeared & are hunters. 25 Worldwide temperatures drop about 4 degrees celsius (39.2 degrees Fahrenheit). -
Holocene (0.0115)
19 The last glacial period ended and sea levels rose, Great Lakes formed. 28 Modern human developed agriculture and used tools made of bronze and iron. -
Anthropocene (Present)
7 Some scientists believe that humankind has caused mass extinctions of plant and animal species, polluted the oceans and altered the atmosphere. 14 This is argument as to when this epoch began, some scientist think it began with the industrial age in the early 1800's other think it began with the atomic age in the 1950's.
