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precambrian
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
B.Romanelli period 6
geological timescale -
cambrian
10 the presence of stromatolites indicates that shallow seas covered much of earth during intervals in this period. 22 trilobites appear. -
ordovician
3 shelled brachiopods appear. 30 colonies of tiny invertebrates call graptolites florished and vibrates appear,fish did not have jaw or teeth and their bodies were covered with bony plates -
silurian
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
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
2 Swamps and forests cover the land 34 Ichthyosaurs are living in the ocean, new invertebrates call ammonite develop -
Pennsylvanian period
4 Giant cockroaches appear 15 Coal deposits form. -
permian
21 Early reptiles resembling large lizards appear 38 Environmental change causes mass extinction of sea invertibrates (trilobites & eurypterids) as the seas retreated. -
triassic
16 Welcome to the world of the Dinosaur! Enter the squirrel sized dinosaur & the first forest dwelling mammals appear 29 Small rodents evolve -
jurassic
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 -
cretaseous
5 First flowering plants appear - angiosperm 35 Impact hypothesis - dinosaur mass extinction. -
eocene
17 Flying squirrels, whales and bats appear 26 First modern horses appear -
oligocene
27 Many early mammal become extinct, clams and snails flourish 32 Antarctic icecaps begin to form -
miocene
8 Appalachian Mountains are created because of the collision of tectonic plates & savannahs form 18 Various species migrated between continents across land bridges -
pliocene
20 Species that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (dire wolf & giant ground sloth) 36 Mediterranean Sea dries up and refills several times due to tectonic forces and dropping sea levels -
Pleistocene
9 Homosapien (modern humans) appeared & are hunters 25 World wide temperatures drop about 4 degrees celsius (39.2 degrees fahrenheit) -
holocene
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 -
paleocene
6 Himalayas develop due to uplifting caused by the Indian subcontinent and the Eurasian continents colliding 12 First primates evolve -
anthropocene
7 Some scientists believe that human kind 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.