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

Permian 290 -250 million years ago Life Dominant life includes: Insects, amphibians, reptiles Evidence of first gymnosperms Climate The supercontinent, Pangea, was centered at the equator, causing the interior of the continent to become dry, with some areas receiving little to-no-rainfall. Geology The supercontinent, Pangea, forms at the equator. North America and Africa collide, causing extreme faulting and folding in the eastern United States. (Alleghany Orogeny) The main rock types/ deposits in PA are sandstone and shale.