Ammonites, a group of now extinct cephalopods with a many chambered spiral shell, evolved into an increasing number of forms. Explosion of reptilian diversity. First frogs and dinosaurs. First mammmals evolve from mammal-like reptiles. At what is now the Grand Canyon, there were warm shallow seas teeming with life. .
First birds appear. .
Pangea begins to rotate. Because different parts rotate at slightly different rates, the continent tears apart. The Gult of Mexico and Atlantic Ocean form on the left side of the Tethys Ocean. Co-evolution of flowering plants and animal polinators. Flowering plants are so successful that they begin to dominate the vegetation. .