The Age of Reptiles started 252 million years ago and ended 66 million years ago. The climate was much warmer than today and the climate was to hot for sea life. The continents were just one supercontinent named Pangea. Pangea was so big that it was in all the directions north, south, east, and west. A major change to landforms is the supercontinent Pangea broke up into the seven continents we have today. At the beginning of the Mesozoic Era reptiles and the first dinosaurs appeared. In the middle of the Mesozoic Era birds and mammals started to appear. Then towards the end of the Mesozoic Era large dinosaurs appeared. At the end of the Era a mass extinction happened and wiped out all the dinosaurs, some mammals and some reptiles. Scientists think a meteor hit the earth to cause the mass extinction.