Final answer:
The distribution of Glossopteris and Mesosaurus fossils supports the theory of continental drift, indicating that these species lived on a connected supercontinent called Pangaea, which has since separated into the current continents.
Step-by-step explanation:
When looking at the distributions of Glossopteris and Mesosaurus fossils, it suggests that these organisms were once distributed over a much more contiguous landmass, which we now understand as the ancient supercontinent Pangaea. This evidence supports the theory of continental drift, where the continents were previously connected and have since drifted apart over millions of years. Fossils of Glossopteris, which are found across different continents (South America, Africa, India, Australia, and Antarctica), and fossils of Mesosaurus, found in both South America and Africa, also indicate that these two continents were once much closer together or connected. The evidence is also supported by the fact that Mesosaurus was a poor swimmer, making it highly unlikely to travel across the wide ocean that currently separates these landmasses.