Geologic Time Scales
Dating from 440-410mya, the Silurian Period saw the first comeback in life on Earth. Recovering from the first mass extinction, plants once again colonized land. Plants were soon followed by terrestrial animals, such as spiders and centipeds. The quick colonization of land was greatly helped by a stabilization of Earth's climate. Still, with the earlier glaciers melting, new habitat in the form of freshwater appeared, fish soon moving into this new area. Coral appeared, slowly growing higher as the melting glaciers added to the ocean level. With the newer habitats of deep and open oceans jawed fish soon dominated in oceans, growing larger with more room to move.