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MAJOR EVENTS ON ERAS - Coggle Diagram
MAJOR EVENTS ON ERAS
MESOZOIC ERA
Age of Reptiles
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Fish, insects, reptiles, and cone-bearing lants called conifers survived.
Reptiles were so successful during this era, that it's sometimes called the Age of Reptiles.
The first dinosaurs appeared during the first period of the Mesozoic era, called the Triassic period.
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Reptiles and Birds
During the Jurassic period, the dinosaurs were the dominant land animals. Scientists were able to identify around several hundred different kinds of dinosaurs, including some that ate plants and some that were predators.
The ocean and seas during this period were also filled with diverse life forms, including sharks, rays, giant marine crocodiles, and plesiosaurs. Plesiosaurs had long neck and paddle-like fins.
Late during the Jurassic period, the first known birds appeared in the skies.
The Archaeopteryx, which means "ancient winged one," is thought to have evolved from a dinosaur.
The sky also had flying reptiles, called pterosaurs, and many varieties of insects.
Flowering Plants
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Reptiles, including dinosaurs, were still widespread throughout the Cretaceous.
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The evolution of flowering plants, or angiosperms, was one of the most important events of the Cretaceous period.
Many flowering plants that we recognize today, first appeared during this time, such as magnolias, figs, and willows.
Mass Extinction
Finalizing the Cretaceous period, another mass extinction occurred.
Scientists believe that this mass extinction occurred when an asteroid struck Earth at a time when extreme volcanic activity in the area that is now India had weakened environments.
This mass extinction wiped out more than half of all plant and animal groups, including the dinosaurs.
PALEOZOIC ERA
The Cambrian Explosion
Many different kinds of organisms evolved, including some that had hard parts such as shells and outer skeletons.
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Animals reach land
During the Devonian period, vertebrates began to live on land.
The first vertebrates were lungfish with strong, muscular fins.
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PreCambrian Time
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Near the end, more complex living things evolved.
Feathery, plantlike organisms anchored themselves to the seafloor, and jellyfish-like organisms floated in the oceans.
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Pangaea is Formed
Over the course of this era, Earth's continents slowly moved together to form a supercontinent, called Pangaea.
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Mass Extinction
During the Permian period, a major change occurred and msot species of life died out during the worst extinction in Earth's history.
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Scientists aren't sure why this mass extinction happened. Many believe it was caused by multiple volcanoes erupted dust and debris that the energy from the sun was blocked.
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Scientists have found that the amount of carbon dioxide in the oceans increased and the amount of oxygen declined.
CENOZOIC ERA
During the Mesozoic era, small mammals had to fight for their food and places where to live. The mass extinction created an opportunity for the species that did survive. During this era, mammals evolved to live in many different environments; on land, in water, and even in the air. Geologists found proof for the spread of mammals in fossils and rocks of the early Cenozoic era.
Mammals Thrive
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During this periods, the Earth's climate became slowly cooler over time.
As continents drifted apart, ocean basins widened and mammals such as whales and dolphins evolved.
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Forests thinned, making space for flowering plants and grasses to become more dominant.
Ice Ages
At the start of the Quaternary period, large sheets of ice began to appear on Earth's surface.
Earth's climate continued to cool and warm in cycles, causing a series of ice ages followed by warmer periods.
During an ice age, about 30% of Earth's surface was covered in thick glaciers.
The latest warm period began between 10,000 and 20,000 years ago. During that time, sea levels rose and most of the glaciers melted.
Humans
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Homo erectus, an ancestor of modern humans, appears in the fossil record near the start of the period, while modern humans appeared about 190,000 years ago.
By about 12,000 to 15,000 years ago, humans had migrated to every continent except Antarctica.