During the Devonian Period the first fish evolved and amphibiansbegan to walk the land, and the first arthropods like insects and spiders also started to multiply. The first seed-bearing plants began to develop huge forests. In the oceans,  the first sharks,deepolped.,along with the first lobe-finned and bony fish. The first ammonite mollusks, and trilobites, appeared the mollusk-like brachiopods, as well as great coral reefs were still very well known. The Late Devonian extinction severely impacted and killed  marine life. The paleogeography was dominated by the supercontinent of Gondwana.