THE CRETACEOUS PERIOD

The Cretaceous period was 105 million years ago also know as the "last age of the dinosaurs"

THE GAS LEVELS DURING THE CRETACEOUS ERA

• There was 22% of oxygen in the atmosphere, dinosaurs lived in a low oxygen world
• 2,072 ppm of co2, making earth ice free

The most dominant species at this time period were the dinosaurs, the four main ones being the Tyrannosaurus, Corythosaurus, Triceratops and Dromaeosaurus.

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• The most dominant plant species were the angiosperms
• Angiosperms are a flower that produces seeds inside a carpel
• Examples of angiosperms are magnoliids, barberry, lauraceae, etc

LANDMASSES DURING CRETACEOUS

• The supercontinent, Pangea, started breaking up in Jurassic, by Mid Cretaceous it had broken up into 7 small continents
• The land structure had contained mountain regions, shallow seas and deep ocean basins

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• The continental plates had not separated just yet.
• Until the coming of the paleogene, during that era, plates started separating into other continents, including the more know one, the Indian Ocean and Eurasian Plates which had formed the Himalayas

THE LAST AGE OF THE DINOSAURS

The "last age of the dinosaurs" was a mass extinction caused by an asteroid followed by a meteor strike afterwards

The extinction didn't exactly kill everything. It's just destroyed every food source for the dinosaurs to eat

• The extinction didn't kill off everything right away, it just destroyed the food source for the dinosaurs
• The carnivores didn't really make father than herbivores due to the rarity of running into a dinosaur

The asteroid had supposedly landed in the Yucatán Peninsula, Mexico. They had named it the Chicixulub impact crater

Works Cited
https://www.britannica.com/science/Cretaceous-Period
http://www.ucmp.berkeley.edu/mesozoic/cretaceous/cretaceous.php
http://media.hhmi.org/biointeractive/earthviewer_web/earthviewer.html