The Silurian began 443 million years ago, and it ended 419 million years ago. It was the period when life started to conquer the land seriously. Mosses and early spore plants built up the first vegetation outside of the water. The seas were ruled by large sea skorpions and smaller squid ancestors. The vertebrates developed jaws with teeth and first fish groups like the cartilaginous and the bony fishes emerged. Huge coral reef areas were built in the shallow seas. The climate was chaotic with a strong alternation between dry and wet conditions, but it was getting warmer again.
On the picture, you can see the large sea scorpion Pterygotus and some squid ancestors. On the ground, there are corals, sponges, trilobites, ostracods, and other sea life. In the water, graptolites and conodonts are swimming. You can also see the so-called spiny shark Climatius. In the background, there are spore plants of the Cooksonia genus.