Answer: The Mesosaurus fossils were distributed in different parts of the world such as South America and South Africa. This fossil was a freshwater organism, a lizard-type reptile and their presence in different places were an evidence which suggested that the continents were once all together, supporting the continental drift theory. As it was too difficult to swim across this huge water body, so the same type fossils are found at two different continents.
The coastlines of South America and South Africa also perfectly fits one another.