Mesozoic+Era

= Mesozoic Era =

Cretaceous Period (146 MYA - 65 MYA) == = Three Major points = = Life and animals =
 * 1) Numerous evolutionary radiations occurred during the Cretaceous.
 * 2) A major extinction occurred at the end of the period.
 * 3) 85% of all species died in the End-Cretaceous (K-T) extinction
 * This period gives us some of the most beloved dinosaurs of modern days.
 * The Cretaceous period saw marked the first time flowering plants began to appear.
 * Oldest knows ants and butterflies begin to appear.
 * Reptiles were largest marine carnivores.
 * Decline of the brachiopods (may be related to diversification of predators)
 * Modern types of crabs appeared
 * The Tyrannosaurus lives during this period.
 * In the ocean all the large reptilian swimmers (mosasaurs, plesiosaurs and giant turtles) all disappeared.

**Localities, Global setting and the environment**
 * High sea levels worldwide.
 * Continents began to move toward their present configuration.
 * Atlantic Ocean widened.
 * <span style="font-family: 'Arial Black',Gadget,sans-serif;">Gondwanaland breaks up.
 * <span style="font-family: 'Arial Black',Gadget,sans-serif;">Temperatures on earth were much warmer. No glaciers.

<span style="color: #008000; font-family: Arial,Helvetica,sans-serif;">The K-T Extinction

 * **Second largest mass extinction in Earths history.**
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Most of the large vertebrates on earth died out. This includes the sea, air and land. **
 * **<span style="font-family: Arial,Helvetica,sans-serif; font-size: small; line-height: normal;">Most mammals, birds, turtles, crocodiles, lizards, snakes, and amphibians were primarily unaffected by the End-Cretaceous mass extinction. **
 * **<span style="font-family: Arial,Helvetica,sans-serif; font-size: small; line-height: normal;">Main theory that explain the K-T extinction: asteroid collided with earth. **

<span style="color: #008000; font-family: 'Arial Black',Gadget,sans-serif; font-size: small;">Asteroid collides with earth

 * **<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: small;">This large impact would cause the earth to be engulfed in a large dust cloud. This would cause sunlight to be blocked. **
 * **<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: small;">Acid rain could be produced. **
 * **<span style="color: #000000; font-family: Arial,Helvetica,sans-serif; font-size: small;">Location of crater is said to be located in the east coast of Yucatan, Mexico. **

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<span style="font-family: 'Comic Sans MS',cursive; font-size: 180%;">Jurassic Period (208 MYA - 146 MYA)




 * At the beginning of the Jurassic Period, the super-continent Pangaea continued to break away. What was a hot and dry climate now gave Pangaea a humid and drippy subtropical feel.**



In the Ocean: <span style="color: #333333; font-family: Arial,sans-serif; font-size: 12px; line-height: 18px;">


 * The oceans were filling up with more life, and at the top of the ocean were the Plesiosaurs along with giant marine crocodiles, sharks, and rays. **



** Life in the ocean was diverse, going from fishlike ichtyosaurs and squidlike cephalopods to coral reefs, sponges and snails to the free floating plankton. **
= = =On Land:= =The Jurassic Period was known as the Age oft the Ruling Reptiles. Because of the green and lush vegetation most dinosaurs were HUGE! =







= The Sky: =



There was also many insects, this included leafhoppers and beetles.
=== While the dinosaurs roamed the earth, many of Earth's earliest mammals scurried around their feet, not knowing that they would dominate the earth once the dinosaurs get wiped out during the end of the Cretaceous Period. ===



Sources: [] []

<span style="font-family: 'Comic Sans MS',cursive; font-size: 180%;">Triassic Period (245 MYA - 208 MYA)

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No dinosaurs were present until late in the Triassic period. New species arose, such as, reptiles, amphibians, frogs, turtles, lizards and crocodiles. The first mammals appeared like the Eozostrodon. Also, Pterosaurs, flying reptiles, were introduced.======

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The Triassic period ended with a mass extinction and volcanic eruptions which caused the super continent, Pangaea, to drift apart. After the extinction and land shifting, new niches were formed. This allowed for the development of dinosaurs…======

Sources: [] @http://www.teachertube.com/viewVideo.php?video_id=53407&title=Triassic_Time_Travel [|http://prehistory.com/triasic.ht]