-
Precambrian 4.6 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
A.Osuna 8
Geological Timescale -
Cambrian 542 MA
1 - There is very little plant life during this period
23 - Shelled brachiopods appear -
Ordovician 488 MA
22 - Trilobites appear
30 - Colonies of tiny invertebrates call graptolites florished and vertebrates 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
31 - Huge plants develop, early amphibians form
37 - Age of fishes, fish that can breath out of water and spend time on land form -
Mississippian 359 MA
2 - Forests cover the land
21 - Early reptiles resembling large lizards appear -
Pennsylvania 318 MA
4 - Giant cockroaches appear
15 - Coal deposits form -
Permian 299 MA
38 - Environmental change causes mass extinction of sea invertibrates (trilobites and eurypterids) as the seas retreat
8 - Appalachian mountains are created because of the collision of tectonic plates & savannahs form -
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 oceans, new invertebrates call ammonite develop -
Jurassic 200 MA
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 MA
5 - First flowering plants appear
35 - Dinosaur mass extinction -
Paleocene 65.5 MA
12 - First primates evolve
25 - World wide temperatures drop about 4 degrees celsius -
Eocene 55.9 MA
17 - Flying squirrels, whales and bats appear
26 - Horses appear -
Oligocene 33.9 MA
27 - Many early mammals become extinct, clams and snails flourish
6 - Himalayas develop due to uplifting caused by the Indian subcontinent and Eurasian continents colliding -
Miocene 23 MA
32 - Antarctic icecaps begin to form
36 - Mediterranean Sea dries up and refills several times due to tectonic forcesa dn dropping sea levels -
Pliocene 5.3 MA
18 - Various species migrated between continents across the bridges
29 - Small rodents evolve -
Pleistocene 1.8 MA
20 - Specie that did not evolve to survive extreme cold moved to warmer climate areas or become extinct (dire wolf & giant ground sloth)
9 - Homosapien (modern humans) appeared & are hunters -
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 scientists believe that human kind has caused mass extinctions of plant and animal species, polluted the oceans and altered the atmosphere
14 - there is arguments 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 1950's
