GEOLOGIC TIME Time scale app?
PRECAMBRAIN Longest era Longest era Earth was inhospitable Earth was inhospitable Still cooling Still cooling No atmosphere No atmosphere
STROMATOLITES Oldest known fossil Oldest known fossil 3.5 billion years 3.5 billion years cynobacteria cynobacteria Began producing oxygen Began producing oxygen Simple cell- no nucleus Simple cell- no nucleus
PALEOZOIC Life flourishes in the ocean Life flourishes in the ocean Trilobites dominate era Trilobites dominate era
Cambrian Multi-cellular life in seas begin Multi-cellular life in seas begin First shells First shells
Ordovician First fish First fish
Ordovician
SILURIAN First land plants First land plants Fern-like Fern-like Sea life continues to flourish Sea life continues to flourish ammonite
DEVONIAN Fish/ sharks Fish/ sharks First insects appear First insects appear
Carboniferous (Mississippian & Pennsylvanian) swampy swampy Huge insects Huge insects Eventually created coal deposits Eventually created coal deposits
PERMIAN Reptiles Reptiles First amphibians First amphibians Life in sea and land thriving Life in sea and land thriving
MASS EXTINCTION THE GREAT DYING 80% of species went extinct!
What happened? Climate got hotter Climate got hotter Siberian traps Siberian traps volcanoes = CO 2 volcanoes = CO 2
MESOZOIC Dinosaurs now dominate Dinosaurs now dominate PANGEA is formed PANGEA is formed
TRIASSIC Beginning of dinosaurs Beginning of dinosaurs Many small Many small Primitive mammals Primitive mammals
JURASSIC Dinosaurs get bigger Dinosaurs get bigger First birds First birds
ARCHAEOPTERYX
CRETACEOUS Intelligent dinosaurs (T- rex, raptors) Intelligent dinosaurs (T- rex, raptors) First flowering plants First flowering plants Carnivorous mammals Carnivorous mammals
MASS EXTINCTION K/T BOUNDARY Dinosaurs go extinct
Asteroid theory Asteroid caused climate change Asteroid caused climate change 1 st - dust blocked out sun 1 st - dust blocked out sun 2 nd - trapped in heat 2 nd - trapped in heat
Evidence for asteroid theory? Crater Crater Irridium Irridium Found in space rocks Found in space rocks Shocked quartz Shocked quartz
CENOZOIC Mammals dominate- Mammals dominate-
Tertiary Mammals Mammals First hominoids First hominoids
Ardi Ardipithecus ramidus 4.4 my 4.4 my
Lucy 3.5 my 3.5 my Bipedal hominid Bipedal hominid
Lucy LUCY
QUATERNARY ice ages ice ages Mammoths/mastodons Mammoths/mastodons Neanderthals Neanderthals
present When will a new geologic time period start? When will a new geologic time period start?
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