-
Precambrian MA: 4,600
Event #10/11: The presence of stromatolites indicates that shalllow seas covered much of Earth during intervals of this period. Nearly half of the valuable mineral deposits in the world occur in the rocks of this period. -
Period: to
B Acosta 8th Period
Geological Timescale -
Palezoic/Cambrian MA: 542
Event #22/23: Trilobites Appear. Shelled brachiopods appear. -
Paleozoic/Ordovician MA: 488
Events #1/30: There is very little plant life during this period. 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. -
Paleozoic/Silurian MA: 444
Event #24/33 Eurypterids (sea scorpions), sea stars, and coral became more common. Vascular land plants and animals, such as scorpions begin to evolve on land. -
Paleozoic/Devonian MA: 419
Events #31/37: Huge plants begin to develop, early amphibians form. Age of Fishes, Fish that can breath out of the water and spend time on land form. -
Palezoic/Carboniferous/Mississippi Period MA: 359
Events #2/21: Swamps and forests cover the land. Early reptiles resembling large lizards appear. -
Palezoic/Carboniferous/Pennsylvanian Period MA: 318
Events #4/15: Giant cockroaches. Coal deposits form. -
Palezoic/Permian MA: 299
Events #8/38: Appalachian Mountains are created because of the collision of tectonic plates & savannahs form. Environmental change causes mass extinction of sea invertibrates ((trilobites & eurypterids) as the seas retreat. -
Mesozoic/Triassic MA: 251
Events #16/34: 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. -
Mesozoic/Jurassic MA: 200
Events #3/13: Flying reptiles called pterosaurs are in the air now. Whoa those dinos are getting big & dominate the land - Lizard hipped and bird-hipped appear - carnivores and herbivores have arrived. -
Mesozoic/Cretaceous MA: 146
Events #5/35: First flowering plants appear - angiosperm. Impact hypothesis - dinosaur mass extinction. -
Cenozoic/Tertiary/Paleocene MA: 65.5
Events #12/29: First primates evolve. Small rodents evolve. -
Cenozoic/Tertiary/Eocene MA: 55.8
Events #17/25: Flying squirrels, whales and bats appear. World wide temperatures drop about 4 degrees celsius (39.2 degrees fahrenheit). -
Cenozoic/Tertiary/Oligocene MA: 33.9
Events #6/27: Himalayas develop due to uplifting caused by the Inidan subcontinent and Eurasian contents colliding. Many early mammal become extinct, clams and snails flourish. -
Cenozoic/Tertiary/Miocene MA: 23
Events #32/36: Antarctic icecaps begin to form. Mediterranean Sea dries up and refills several times due to tectonic forcesa dn dropping sea levels. -
Cenozoic/Tertiary/Pliocene MA: 5.3
Events #18/26: Various species migrated between continents across land bridges. First modern horses appear. -
Cenozoic/Quaternary/Pleistocene MA:1.8
Events #9/20: Homosapien appeared & are hunters. Species that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (dire wolf & giant ground sloth). -
Cenozoic/Quaternary/Holocene MA: 0.0115
Events #19/28: The last glacial period ended and sea levels rose, Great Lakes formed. Modern Human developed agriculture and used tools made of bronze and iron. -
Cenozoic/Quaternary/Anthropocene MA: Current date.
Events #7/14: Some scientists believe that human kind has caused mass extinctions of plant and animal species, polluted the oceans and altered the asmosphere. There is argumentas to when this epoch began, some scientists think it began with the atomic age in the 1950's.
