-
Precambrian Time
Event 10- The presence of stromatolites indicates that shallow seas covered much of earth during intervals in this period.
Event 11- Nearly half of the valuable mineral deposits in the world occur in the rocks of this period. -
Period: to
F. Chamorro P-6
Geologic Timescale -
Cambrian
Event 22- Trilobites appear
Event 23- Shelled brachiopods appear -
Ordovician
Event 1- There is very little plant life during this period
Event 30- Colonies of tiny invertebrates called graptolites flourished and vertebrates appear, Fish did not have jaws or teeth and their bodies were covered with bony plates. -
Silurian
Event 24- Eurypterids (sea scorpion), sea stars and coral become more common.
Event 33- Vascular land plants and animals, such as scorpions begin to evolve on land. -
Devonian
Event 31- Huge plants begin to develop, early amphibians form.
Event 37- Age of fishes, fish that can breath out of the water and spend time on land form. -
Mississippian epoch
Event 2- Swamps and forests cover the land
Event 21- Early reptiles resembling lizards appear. -
Pennsylvanian epoch
Event 4- Giant cockroaches appear
Event 15- Coal deposits form. -
Permian
Event 8- Appalachian Mountains are created because of the collision of tectonic plates & savannahs form.
Event 38- Environmental change causes mass extinction of sea invertebrates (trilobites & eurypterids) as the seas rettreat. -
Triassic
Event 16- Welcome to the world of the dinosaur! Enter the squirrel-sized dinosaur & the first forest dwelling mammals appear.
Event 34- Ichthyosaurs are living in the ocean, new invertebrates called smmonite develop. -
Jurassic
Event 3- Flying reptiles called pterosaurs are in the air now.
Event 13- Whoa those dinos are getting big & dominate the land - Lizard-hipped and bird-hipped appear - carnivors and herbivores have arrived. -
Cretaceous
Event 5- First flowering plants appear- angiosperm.
Event 35- Impact hypothesis- dinosaur mass extinction. -
Paleocene
Event 12- First primates evolve
Event 29- Small rodents evolve -
Eocene
Event 17- Flying squirrels, whales and bats appear
Event 25- World wide temperatures drop about 4 degrees celsius (39.2 degrees farenheit) -
Oligocene
Event 6- Himalayas develop due to uplifting caused by the Indian subcontinent and Eurasian continents colliding.
Event 27- Many early mammals become extinct, clams and snails flourish. -
Miocene
Event 32- Antarctic ice caps begin to form.
Event 36- Mediterranian Sea dries up and refills several times due to tectonic forces and dropping sea levels. -
Pliocene
Event 18- Various species migrated between continents across land bridges.
Event 26- First modern horses appear -
Pleistocene
Event 9- Homosapien (modern humans) appeared & are hunters
Event 20- Species that did not evolve to survive extreme cold moved to warmer climate areas or became extinct (dire wolf & giant ground sloth) -
Holocene
Event 19- The last geological period ended and sea levels rose, Great Lakes formed
Event 28- Modern human developed agriculture and used tools and made of bronze and iron.
