Species affected in this mass extinction were the reef livers. However, the most affected were the Placodermi, or jawless fish (7). If the corals were gone, then the small species in the corals died. When those died, the ripple was already established in the food chain which would bring down, and result in massive extinction.
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During the Carboniferous Era, that lasted from 360-290 million years ago (5), there were many large forests (8). During this time, the ferns grew to be over 10m tall. When the ferns died, they fell back into the swamps they were living in and over made coal (9). These large ferns were taken down by the invasion of seeds (5). There was a lot of ecological competition and the seeds won out by spreading into the swamps of the ferns. Through seeds, the ferns could not survive and died off because there were not enough supplies to meet the demands of both species of plants (9). Ferns grew in swamps because they needed the moist area to reproduce. Without out the water they could not reproduce. When the ferns started to die, they fell back into the swamps. Decomposition could not occur because there was no oxygen in the water. So, the ferns were buried and eventually turned to coal (10).
During the Permian mass extinction about 248 million years ago, the greatest extinction in history occurred. During this time 90-95%of all marine species became extinct (5). It is believed, yet still highly debated, that the cause of the Permian extinction was due to the glaciation on Gondwana. Gondwana was a large land mass. During the glaciation, a production of cooler climates and a world wide lowering of sea levels lead to marine life extinctions.
Another theory which explains the mass extinctions of the Permian is the reduction of shallow continental shelves due to the formation of the super-continent Pangea. Such a reduction in oceanic continental shelves would result in ecological competition for space, perhaps acting as cause for extinction.
