-
The Earth is created
-
~The Earth is created 4.3 billion years ago
~Precambrian represents the bulk of Earth's history before Cambrian
~Precambrian covers nearly 90% of Earth's history
When the crust cooled, huge pieces of the crust began to move in different directions these pecies of crust are called tectonic plates -
The Precambrien Era ends.
-
The begining of the Paleozoic Era.
-
The begining of Cambrian period.
-
~The first geological time period of the Paleozoic Era
~It lasted about 53 million years
~Marked a dramatic burst of evolutionary changes in life on Earth, known as the "Cambrian Explosion” -
The Cambrian period ends.
-
Ordovician period begins.
-
~Fairly warm climate
~Life still primarily under water but more animal forms
~Groups of algae evolved along the edges of the water
~Fungi and algae left on the bare land worked together to create lichen -
Ordovician period ends.
-
Silurian period begins.
-
~The warm shallow seas made good conditions for marine life to grow
~The species that survived the mass extinction at the end of the Ordovician Period spread out and developed new variations of life
~One of the survivors were the nautiloids -
Silurian period ends.
-
Devonian period begins.
-
~Laying close to the equator made the climate of the Devonian was warm
~The warm temperatures made life on land very good for plants
~The Devonian is known as the Age of Fishes because it is famous for the species of fish that developed in Devonian seas -
Devonian period ends.
-
The Carboniferous begins.
-
~In the early Carboniferous Period, the Mississippian Epoch, much of North America was covered with warm and shallow seas
~In the middle through late Carboniferous Period, the land was rising out of the water
~The end of the Carboniferous Period is marked by global climate changes caused by glaciers that covered the South Pole -
Carboniferous period ends.
-
Permian period begins.
-
~The Permian Period was the final period of the Paleozoic Era
~On land, the giant swamp forests of the Carboniferous began to evaporate and dry out
~Fossils of the shallower coastal waters around Pangaea’s continental shelf show that reefs were large and diverse ecosystems with numerous sponge and coral species -
Cretaceous period begins.
-
Jurassic period ends.
-
~In Gondwana, South America and Africa broke apart because the ocean floor was spreading along a crack in the earth’s crust called a rift
~The rift between Africa and South America created a long chain of volcanic mountains underwater which grew as the Atlantic Ocean
~Animal life continued to develop much as it had in the Jurassic as new species of dinosaurs became important -
Cretaceous period ends.
-
Tertiary period begins.
-
Mesozoic Era ends.
-
Cenozoic Era begins.
-
~The beginning of this period was very warm and moist compared to today’s climate as much of the earth was tropical or sub-tropical and Palm trees grew as far north as Greenland
~During the Pliocene Period the first hominids appeared these were our human ancestors
~Birds did almost as well as mammals during the Tertiary Period and many of the birds we know today were present -
Tertiary Era ends.
-
Quaternary period begins.
-
~Generally temperatures were cooler everywhere on earth during this time period
~During the Quaternary period the positions of the continents were very much the same as they are today
For us, the most important development of the Quaternary ~Period is the development of the hominids or Humans -
Mesozoic Era begins.
-
-
Triassic period begins.
-
~Many species that survived the Permian Extinction died out during the early part of the Triassic like Trilobites, bryozoans, and rugose
~A completely new invertebrate species that developed in the Triassic was the Belemnite
~The most important development was happening to the reptiles. These animals would dominate the land, sea and air throughout the Mesozoic Era -
Triassic period ends.
-
Jurassic period begins.
-
~During the Jurassic Period, the supercontinent Pangaea split apart into two peices
~The climate in the Jurassic Period was warm and stable
~Many types of animals and plants developed in the Jurassic Period -
Paleozoic period ends.
