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1 CE
The Beginning of Earth
4.5 billion years ago - Earth was created. -
2
Ordovician
444 million years ago- 86% of the species, Graptolite, was lost. Graptolites were sea creatures; they were filter-feeding animals and colony builders. Their demise was caused by a short, but severe ice age that lowered sea levels and triggered the uplift of the Appalachians. The newly exposed silicate rock sucked CO2 out of the air, which made the planet colder.
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3
Devonian
375 million years ago- 75% of the species, Trilobite, was lost. Trilobites were the most diverse and abundant animal; their great success was due to their spiky armour and multifaceted eyes. Their death was caused by newly emerged plants covering the planet and releasing nutrients into the ocean. This caused algal blooms to suck oxygen out of the water, suffocating the trilobites.
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4
Permian
251 million years ago- 96% of the species, Tabulate Coral, was lost. This extinction was caused by a perfect storm of natural catastrophes. A cataclysmic eruption in Siberia blasted CO2 into the atmosphere, which caused methanogenic bacteria to release methane. Global temperatures rose and oceans acidified. This was by far the worst extinction the world has ever seen.
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5
Triassic
200 million years ago- 80% of the species, Conodont Teeth, were lost. No clear cause has been found as to what caused the extinction.
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6
Cretacious
66 million years ago- 76% of the species, Ammonite and Dinosaurs, were lost. Volcanic activity and climate change already had the species under stress, but when the steroid hit the earth that was the last blow.
