200 million years from now; a new supercontinent has formed.
The land masses have all amalgamated, forming a single continent. 225 million years before mankind, the supercontinent was called Pangaea; and this new land mass is Pangaea ll. North and South America have joined the other continents. A single global ocean surrounds Pangaea ll.
A single landmass like this creates a world of extreme climates. The Earth has now one ocean, circulating one massive continent. The ocean is so massive that from space some views would show the earth as pure blue orb of ocean. The single sea - the Global Ocean - has a huge anticlockwise current circulating around the southern hemisphere. Life can migrate easily in this powerful current.
Because of this powerful current, there is little water movement between north and south. As a result, there is a steep temperature gradient between high and low latitudes. The single ocean supports complex food chains and highly-evolved species.
A mass extinction has affected life on land and in the seas. Clouds of ash and an increase in acidity killed the plankton in the surface water. The ocean food chain collapsed. Many bony fish died out. Their place was taken by surviving creatures from the deep.