505-570 MYA Ordovician 438-505 MYA Surface of the Climate Organisms Present Firsts? Newly Extinctions? yes Time Period Earth/Atmosphere (include ice Other (plants/animals) evolved or no (gases) ages here) Silurian 408-438 MYA Devonian 360-408 MYA
505-570 MYA Ordovician 438-505 MYA Time Period Surface of the Earth/Atmosphere (gases) Climate (include ice ages here) Organisms Present (plants/animals) Firsts? Newly evolved Extinctions? yes or no Other Silurian 408-438 MYA Devonian 360-408 MYA