ERA PERIOD AGE (of start) Cenozoic Quaternary 1.6 my Tertiary 65 my Mesozoic Cretaceous 140 my Jurassic 205 my Triassic 250 my Paleozoic Permian 290 my Carboniferous 355 my Devonian 410 my Silurian 438 my Ordovician 510 my Cambrian 540 my

Tertiary 65 -1.6 million years ago Life Dominant life includes: Birds, mammals, bony fish, angiosperms (flowering plants), grasses First primates and "humans" Mammals and birds fill the areas where dinosaurs used to be Climate The climate was very warm (much more than today) with warm swamps and alligators at the North Pole! Geology There was a lot of weathering and erosion at this time, creating the landscape that you see today. The main rock types/ deposits in PA are silt, gravel and sand.