Phanerozoic of Pangaea into Laurasia and Gondwana in an extinction known as the Jurassic-Cretaceous extinction. Sea levels rose, destroying fern prairies and creating shallows. Ichthyosaurs became extinct whereas sauropods, as a whole, did not; in fact, some species, like "Titanosaurus", lived until the K-T extinction. The increase in sea-levels opened up the Atlantic sea way which would continue to get larger over time. The divided world would give opportunity for the diversification of new dinosaurs. The Cretaceous is the longest period in the Mesozoic, spans from 145 million to 66 million years ago, and is divided into two epochs: Early Cretaceous,
Orcombe Point cliffs further east. The coastal exposures along the coastline provide a continuous sequence of Triassic, Jurassic and Cretaceous rock formations spanning approximately 185 million years of the Earth's history. The localities along the Jurassic Coast includes a large range of important fossil zones. Orcombe Point is the western end of the Jurassic Coast and the South West Coast Path includes the entire length of the site. The ascent to Orcombe Point shows the successive layers of different sedimentary rocks, which were deposited under varying geological conditions. At the base are cross-bedded sandstones. Towards the top, the rock types are those