Transcript Geological - CLC Science Wiki

Geological
Timeline
Heather Mortensen
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.
Bacteria
Blue-green Algae
Colonial Algae
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
Fish
Coniferous Plants Amphibians
Sharks
Reptiles
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.
Dinosaurs
Flowering Plants
Crocodiles
Ants
Bees
Butterflies
Flies
Snakes
Cenozoic Era
65 million years ago through today
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.
Elephants
Giraffes
Rodents
Pigs
Horses
Dogs
Monkeys
Whales
Deer
Sloth
Cats
Humans
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 sabertoothed 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.
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.
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.
Bibliography
http://en.wikipedia.org/wiki/Ice_age#Major_ic
e_ages
http://www.enchantedlearning.com/subjects/G
eologictime.html
http://www.google.ca