1. Geological Timeline Heather Mortensen

2. Precambrian Era : Hadean Eon 4.6 to 3.9 billion years ago, Archean Eon 3.9 to 2.5 billion years ago, Proterozoic Eon 2.5 billion years ago to 540 million years ago During the Hadean Eon the Earth’s continental and oceanic crust began to solidify. It wasn’t till the Archean Eon when the first life forms appeared and began to release oxygen into the atmosphere. These life forms were blue-green algae, Achaeans, and bacteria. During the Proterozoic Eon the first multi-celled life forms started to appear : colonial algae and soft-bodied invertebrates. Blue-green Algae Bacteria Colonial Algae

3. Paleozoic Era 540 to 248 million years ago The Paleozoic Era was the “Age of Trilobites”. The first vertebrates and the earliest known primitive fish were created. At the end of the Cambrian Period there was a mass extinction of trilobites. During the Ordovican Period primitive plants started to appear on land. Also the first corals, seaweed, and fungi appeared. The first amphibians, bony fish, and sharks appeared during the Devonian Period. The Pennsylvanian and Mississippian Periods was when the first reptiles, winged insects, ferns, and cockroaches appeared. In the Permian Period amphibians and reptiles dominated. At the end of the Permian Period and the whole Paleozoic Era there was the largest mass extinction. The trilobites went extinct, 50% of all animal families, 95% of all marine species, and many trees. This extinction may have been causes by glaciations or volcanism. Trilobites FishConiferous Plants Amphibians Sharks Reptiles

4. Mesozoic Era 248 to 65 million years ago The Mesozoic Era was “The Age of Reptiles”. The first dinosaurs, mammals, turtles, and flies appeared during the Triassic Period. In the Jurassic Period more dinosaurs, birds, and flowering plants appeared. The Cretaceous Period was the last period of the Mesozoic Era. The first crocodiles, feathered dinosaurs, earliest known butterflies, snakes, ants, and bees appeared. The Cretaceous Period ended with a large extinction of dinosaurs. DinosaursFlowering Plants Crocodiles Butterflies Snakes Ants Bees Flies

5. Cenozoic Era 65 million years ago through today Horses Dogs Monkeys Whales SlothHumans ElephantsGiraffes Rodents Pigs Deer Cats The Cenozoic Era is known as “The Age of Mammals”. During the Tertiary Period the first large mammals, primitive primates and whales, and rodents appeared. Many of the mammals were pigs, deer, cats, and rhinos. Also horses, dogs, bears, modern birds and whales, and monkeys appeared. During the Quaternary Period, “The Age of Man”, the first humans evolved. Mammoths, saber-toothed cats, and sloth's appeared. After the last ice age. About 10,000 years ago, there was a mass extinction of large mammals, and many birds.

6. Mammoths & Saber-toothed Cats Mammoths lived from about 2 million years ago to 9,000 years ago, during the last ice age. They were elephant like animals that adapted to cold whether and lived all over the world. Mammoths were herbivores (plant eaters), and ranged from 9ft to 15ft tall. Smilodon was the largest saber- toothed cat. It was about 4-5 ft long, 3ft tall, and weighed about 440 pounds. The canine teeth of these cats were about 7 inches long. The Smilodon lived about 1.6 million years to 11,000 years ago. Saber-tooth cats also went extinct after the last ice age because they couldn’t adapt to the warmer whether. Saber-toothed cats, mammoths, and other large mammals from that period of time are mostly known from fossils, frozen mummified carcases, and from ancient cave drawings.

7. Formation of our Atmosphere The formation of the Earth’s atmosphere was formed about 4.55 billion years ago by planetary degassing. Planetary degassing is a process when gases like carbon dioxide, sulphur dioxide, and nitrogen are released from the interior of the Earth from volcanoes and other processes.

8. Ice Ages Ice ages happen when there is a reduction in the temperature of Earth’s surface and atmosphere for a long period of time. This results in an expansion of continental and polar ice sheets, and alpine glaciers. There have been about 7 recognizable ice ages but only 4 of them are considered significant because of how long they were or because of their glaciation : ~about 2 million years ago to the present - the Quaternary Ice Age ~350 to 250 million years ago - the Karoo Ice Age ~800 to 600 million years ago - the Cryogenian (or Sturtian-Varangian) Ice Age ~2400 to 2100 million years ago - the Huronian Ice Age.

9. Bibliography http://en.wikipedia.org/wiki/Ice_age#Major_ic e_ages http://en.wikipedia.org/wiki/Ice_age#Major_ic e_ages http://www.enchantedlearning.com/subjects/G eologictime.html http://www.enchantedlearning.com/subjects/G eologictime.html http://www.google.ca