The presence of Mesosaurus fossils tells us that South America, Africa, and Antarctica were once connected and shared a similar environment, which means they were once a big continent. The remains of Mesosaurus, a crocodile-like reptile, are found in rocks in both South America and Africa. The distribution of Mesosaurus fossils suggests that South America and Africa were once physically connected. Mesosaurus lived during the early Permian period, which was around 286 to 258 million years ago. If the continents were still in their present positions, it would have been impossible for Mesosaurus to swim across such a large body of ocean as the Atlantic because it was a coastal animal. Therefore, the presence of Mesosaurus fossils supports the theory of Pangaea, a supercontinent that existed around 300 million years ago.