-
Precambrian 4,600 MA
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
R. Murgueytio P.3
Geological Timescale -
Cambrian 542 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 flourished and vertebrates appear, fish did not have jaws or teeth and their bodies were covered with boney 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
31.) Huge plants begin to develop, early amphibians form.
37.) Age of fishes, fish that can breathe out of the water and spend time on land form -
Mississpian Period 359 MA
2.) Swamps and forests cover land
21.) Early reptiles resembling large lizards appear -
Pennsylvanian Period 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 and savanas form.
38.) Environmental change causes mass extinction of sea invertebrates (trilobites and eurypterids) as the seas retreat. -
Triassic 251 MA
16.) Welcome to the world of the dinosaur! Enter the squirrel-sized dinosaur and the first forest dwelling mammals appear.
34.) ichthyosaurs are living in the ocean, new invertebrates call ammonite develop. -
Jurassic 200 MA
3.) Flying reptiles called pterosaurs are in the air now.
13.) whoa, these dinos are getting bigger and dominate the land-lizard-hipped appear- carnivores and herbivores , have arrived. -
Cretaceous 146 MA
5.) First flowered plant appears.
35.)Impact hypothesis-dinosaur mass extinction -
Paleocene 65.5 MA
12.) First primates evolved
29.) Small rodents evolve -
Eocene 55.8 MA
17.) flying squirrels, whales and bats appear.
25.) Worldwide temperature drop about 4 degrees celsius (39.2 fahrenheit) -
Oligocene 33.9 MA
5.) the himalayas develop due to uplifting, causied by the indian subcontinent and Eurasion continents colliding.
27.) many early mammals become extinct, clams and snails flourish -
Miocene 223 MA
32.) antartica caps 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 horses appear -
Pleistocene 1.8 MA
9.)homo sapien (modern humans) appeared and are hunters .
20.)species that didn't evolve to survive extreme cold moved to warmer climates areas or became extinct(dire wolf and giant ground sloth) -
Holocene 0.0115 MA
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 Current Date
7.)some scientist believe that human kind has caused mass extinctions of plants and animal species, polluted the oceans and altered the atmosphere.
14.)there is an argument as to when this epoch began, some scientist think it began with the industrial age in the early 1800's others think it began with the atomic age in the 1950's.
