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Pre Cambrian
The presence of stromatolites indicates that shallow seas covered much of earth during intervals in this period. Nearly half of the valuable mineral deposits in the world occur in the ricks of this period. -
Period: to
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Geologic Timescale -
Cambrian
Trilobites appear and shelled brachiopods appear. -
Ordovician
Colonies of tiny invertebrates call graptolites florished and vertebrates appear, Fish do not have jaws or teeth and their bodies were covered with bony plates. There is very little plant life during this period. -
Silurian
Eurypterids (sea scorpions), sea stars, and coral become more common. Vascular land plants and animals, such as scorpions begin to evolve on land. -
Devonian
Huge plants begin to develop, early amphibians form. Age of fishes, fish that can breathe out of water and spend time on form. -
Carboniferous Mississippian Period
Swamps and forests cover the land. Early reptiles resembling large lizards appear. -
Carboniferous Pennsylvanian Period
Giant cockroaches appear. Coal deposits form. -
Permian
Appalachian Mountains are created because of the collision of tectonic plates & savannah forms. Environmental change causes mass extinction of sea invertebrates (trilobites & eurypterids). -
Triassic
Welcome to the world of the dinosaur! Enter the squirrel sized dinosaur & the first forest dwelling mammals appear. Ichthyosaurs are living in the ocean, new invertebrates call ammonite develop. -
Jurassic
Flying reptiles called pterosaurs are in the air now. Whoa these dinos are getting big & dominate the land- Lizard-hipped and bird-hipped appear - carnivores and herbivores have arrived. -
Cretaceous
First flowering plants appear - angiosperm. Impact hypothesis - dinosaur mass extinction. -
Tertiary Paleocene
First primates evolve. Small rodents evolve. -
Tertiary Eocene
Flying squirrels, whales and bats appear. World wide temperature drops about 4 degrees celsius (39.2 degrees Fahrenheit). -
Tertiary Oligocene
Himalayas develop due to uplifting caused by the Indian subcontinent and Eurasian continents colliding. -
Tertiary Miocene
Antarctic icecaps begin to form. Mediterranean Sea dries up and refills several times due to tectonic forcesa dn dropping sea levels. -
Tertiary Pliocene
Various species migrated between continents across land bridges. First modern horses appear. -
Quaternary Pleistocene
Homosapien (modern humans) appeared and are hunters. Species that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (dire wolf and giant ground sloth). -
Quaternary Holocene
The last glacial period ended and sea levels rose, Great Lakes formed. Modern human developed agriculture and used tools made of bronze and iron. -
Quaternary Anthropocene
Some students believe that human kind has caused mass extinctions of plant and animal species, pollutes the oceans and altered the atmosphere. There is argument as to when this epoch began, some scientists think it began with the industrial age in the early 1800's others think it began with the atomic age in the 1950's.
