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Precambrian. 4600MA
(10) The presence of stromatolites indicates that shallow seas covered much of 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
S Bhansali P8
Geological Timescale -
Cambrian. 452 MA
(22) Trilobites appear (23) Shelled brachiopods appear -
Ordovician. 488 MA
(1) There is very little plant life during this period (30) Colonies of tiny invertebrates call graptolites florished and vertibrates appear, Fish did not have jaws or teeth and their bodies were covered with bony plates -
Silurian. 444 MA
(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 MA
(37) Age of Fishes, fish that can breath out of the water and spend time on land form (31) Huge plants begin to develop, early amphibians form -
Mississippian. 359 MA
(2) Swamps and forests cover the land (21) Flying reptiles called pterosaurs are in the air now -
Pennsylvanian. 318 MA
(4) Giant cockroaches appear (15) Coal deposits form -
Permian. 299 MA
(8) Appalachian Mountains are created because of the collision of tectonic plates & savannahs form (38) Environmental change causes mass extinction of sea invertibrates (trilobites & 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 call ammonite develop -
Jurassic. 200 MA
(13) Whoa those dinos are getting big & dominate the land - Lizard-hipped and bird-hipped appear - carnivores and herbivores have arrived (3) Flying reptiles called pterosaurs are in the air now -
Cretaceous. 146 MA
(35) Impact hypothesis - dinosaur mass extinction (5) First flowering plants appear - angiosperm -
Paleocene. 65.5 MA
(12) First primates evolve (29) Small rodents evolve -
Eocene. 55.8 MA
(25) World wide temperatures drop about 4 degrees celsius (39.2 degrees fahrenheit) (17) Flying squirrels, whales and bats appear. -
Oligocene. 33.9 MA
(6) Himalayas develop due to uplifting caused by the Indian subcontinent and Eurasian continents colliding (27) Many early mammal become extinct, clams and snails flourish -
Miocene. 23 MA
(32) Antarctic icecaps begin to form (36) Mediterranean Sea dries up and refills several times due to tectonic forces and dropping sea levels -
Pliocene. 5.3 MA
(18) Various species migrated between continents across land bridges (26) First modern horses appear -
Pleistocene. 1.8 MA
(9) Homosapien (modern humans) appeared & are hunters (20) Species that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (dire wolf & giant ground sloth) -
Holocene. .0115. MA
(28) Modern human developed agriculture and used tools made of bronze and iron (19) The last glacial period ended and sea levels rose, Great Lakes formed -
Anthropocene. Current Date
(7) Some scientists believe that human kind has caused mass extinctions of plant and animal species, polluted the oceans and altered the atmosphere (14) There 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
