Geological Timescale PDF

CENOZOIC EON ERA PERIOD EPOCH Holocene Holocene extinction (Anthropocene), 6th mass extinction caused by human activity M.Y. 0.012 Hawaii (big island) eruptions start - 0.7 MY Pleistocene (previously) Quaternary Holocene extinction includes the disappearance of large land animals known as mega...

CENOZOIC EON ERA PERIOD EPOCH Holocene Holocene extinction (Anthropocene), 6th mass extinction caused by human activity M.Y. 0.012 Hawaii (big island) eruptions start - 0.7 MY Pleistocene (previously) Quaternary Holocene extinction includes the disappearance of large land animals known as megafauna, starting at the end of the last glacial period. abrupt change in climate, the result of comet (Younger Dryas) impact, human overkill and disease Middle has rise of Homo Sapiens La Brea Tar Pits (LA) Lagerstatten 2.6 Earliest humans - 2 MY Pliocene 5.3 Neogene Phanerozoic Miocene Cenozoic (Age of Mammal) 23.0 Oligocene Start of Antarctica glaciation 33.9 Tertiary Eocene Paleogene Green River Formation Lagerstatten First Modern horse 56.0 Paleocene Massive volcanic activity marking opening of north Atlantic Ocean - 60 MY 66.0 MESOZOIC EON ERA PERIOD EPOCH M.Y. Cretaceous most continents separated, mass extinction at end of period including dinosaurs, ammonites, mollusks, foraminfera, with distinctive spiral shells. Deccan Traps and asteroid hitting Yucatan Peninsula caused -first flowering plants Crocodile arrive, rudist become major reef builders Upper 100.5 Lower Yixian Formation(China) Lagerstatten Jurassic first birds, gymnosperms dominate, evolution of angiosperms bird hipped dino appear, rudist bivalve Dinosaurs exploded after extinction event Flowering plants appear 140 MY 145.0 Upper 163.5 Middle 174.1 Solnhofen Limestone (Germany) Lagerstatten Lower Phanerozoic Mesozoic (Age of Reptile) Archaeopteryx First appeared First birds - 200 MY 201.3 Triassic Mass extinction at end caused by massive eruptions in hot spot at the center of what would eventually be the Atlantic Ocean Upper (lizard hipped dino appear) Ghost Ranch (NM) Lagerstatten Break-up of Pangaea begins 225 MY 237 continents begin to separate, first dinosaurs, first mammals, bivalve & echinoids expand loss of synapsids cleared the path for the earliest dinosaurs and the first mammals. One branch of synapsid. First mammals - 225 MY Middle Dinosaurs appear - 240 MY 247.2 Lower 251.9 PALEOZOIC EON ERA PERIOD EPOCH Permian Upper Pangaea, glaciations, WORST mass extinction of life at end of this period. Widespread volcanic activity across Siberia which acidified ocean, wildfires. 96% life disappear including last trilobites, graptolites, and blastoids. Turtles came to be Sponges appeared Carboniferous (Age of Insects & Age of Amphibians) Gondwanaland and small northern continents form, early winged insects, first reptiles tetrapods, four-limbed animals thrived after mass extinction Lots of swamps - coal, oil formed from plants of this time Mazon Creek Lagerstatten Pennsylvanian (alternately terrestrial and marine, SWAMPS) Clams? Amphibian many Mississippian (heavily marine, limestone, crinoids) Reptile evolve Devonian (Age of Fish) Phanero zoic Paleozoic Middle Lower Upper Middle Lower Upper Middle Lower M.Y. 259.1 273.0 298.9 307.0 First reptiles - 310 MY 315.2 323.2 330.9 346.7 358.9 Start of supercontinent Pangaea - 360 MY Tiktaalik HAS ARRIVED, amphibians evolve diversification of bony fishes, first seeded plants Upper First amphibians - 370 MY mass extinction at the end of this period (pulse in series of climate changes. AKA Hangenberg crisis: explosion of a nearby star that caused long-lasting ozone depletion) Placoderms, more trilobites, and reef building invertebrates, coral died. Middle 382.7 393.3 419.2 Silurian earliest terrestrial vascular plants Sponges flourished after mass extinction, major reef building Lower Pridoli 423.0 Ludlow Wenlock 427.4 433.4 Early land plants - 438 MY First bony fish (Osteichthyes), Acanthodians (first jawed fish) Ordovician (Age of Invertebrates) diversification of invertebrates, suspension feeders dominate Plants move to land mass extinction at the end of this period (pulse ice sheets, change ocean currents, wiped out most trilobites, many coral, and some brachiopods) Llandovery Upper Middle 463.8 458.4 470.0 485.4 Lower Beecher’s Trilobite Bed Furongian Cambrian (Age of Invertebrates) Cambrian Explosion of Life Burgess Shale Lagerstatten marine animals diversify, diverse algae, jawless fish 497 First fish - 505 MY Epoch 3 Epoch 2 Terreneuvian 509 521 541.0 EON PRECAMBRIAN EON Proterozoic M.Y. 541.0 earliest eukaryotes, trace animal fossils, first multicellular fossils Significant oxygen in atmosphere 1500 MY Precambrian (87% of Earth’s History) 2 snowball earths 750- 635 Early eukaryotes - 1900-1700 MY Rodinia supercontinent existed between 1.1 billion and 750 million years ago Rodinia broke up in the first period of the Neoproterozoic First snowball earth & atmosphere becomes oxygen rich 2500 Archean origin of life, beginning of photosynthesis, increased abundance of oxygen in atmosphere, diversification of prokaryotes Start of Photosynthesis 3200 First bacteria - 3500 MY Oldest rocks yet discovered - 3950 MY Late Heavy Bombardment 4,000 Ocean first forms 4000 4000 Hadean Late Heavy Bombardment ended this Eon. Young atmosphere probably made up of CO2, H2O, CH4, & NH3 4527 Formation of Moon Formation of Earth - 4600 MY 4600