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The Silurian Period, 438-410 million years ago, was the time when the colonisation of land above seal level is believed to have started. Before then, life had been entirely confined to the waters. The first shark scales are recorded in the early silurian followed by the first fishes with jaws and the first bony fishes. The earliest tracks on land (the sea scorpion "eurypterid") date back to the Late Silurian.During the Silurian period, vascular plants were introduced to the world. Vascular plants are what we usually think of when we think of plants. They differ from green algae in both the internal and external structure in that they are adapted to withstand the force of gravity and have the ability to retain water. |
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