Saskatchewan Time Scale By justicebrie12345 Period: 5 BCE to 2 BCE Bison come to north america Period: 2 BCE to 1 BCE Humans come to north america Period: 1 BCE to 1 BCE origin of the praries Period: 2 to 5 BCE Ice age begins Period: 50 to 2 Climate changes, Sk plateau develops Period: 65 to 50 Extinction of the dinosaurs Period: 66 to 65 Triceratops roam SK Period: 70 to 66 Swamps, rivers, and lakes form the badlands Period: 75 to 70 Shallow sea begins to retreat Period: 100 to 75 Diamonds are brought to the surface of SK in volcanic pipes Period: 213 to 100 SK is again covered by a shallow sea Period: 220 to 213 First Mammals Period: 245 to 220 First Dinosaurs Period: 248 to 245 Mass extinction in the oceans, 90% of the species disappear Period: 355 to 248 First amphibians Period: 385 to 355 Potash is deposited in the shallow sea that covers SK Period: 390 to 385 Winnipegosis Reefs are deposited, later to become a trap for oil deposits Period: 470 to 390 Tyndall Stone deposited as massive limestone Period: 478 to 470 Meteorite hits SK, leaving behind the Carswell Meteorite Crater Period: 544 to 478 Sk covered by the epicontinental Sauk Sea Hard Shelled invertabrates including Trilobites Period: 1300 to 544 Uranium Deposited Period: 1700 to 1300 Erosion of the mountains Period: 1800 to 1700 Orogeny (mountain building) Trans-Hudson Orogen Period: 1850 to 1800 Wathaman Batholith (an intrusion of magma under the surface) Period: 1900 to 1850 Volcanoes in SK Period: 2100 to 1900 Break up of the ancient continent, creation of a large ocean Period: 2500 to 2100 Saskatchewan is part of large ancient continent Period: 4600 to 2500 Earth is formed