Final answer:
The fossils of Lystrosaurus and the coelacanth provide substantial evidence for the existence of Pangaea due to their distribution across widely separated continents and their biological traits that imply a lack of long-distance dispersal across oceans.
Step-by-step explanation:
When choosing two fossils as evidence for the existence of the large landmass Pangaea, we can consider the Lystrosaurus and the coelacanth. The Lystrosaurus was a land-dwelling reptile from the Early Mesozoic era whose fossils have been found in widely separated regions, including Africa, India, and Antarctica. The discovery of lystrosaurus fossils in these diverse locations which are now separated by vast oceans suggests these continents were once connected, supporting the concept of Pangaea. Additionally, the fact that the lystrosaurus laid eggs on land and was a poor swimmer indicates it could not have dispersed across oceans, reinforcing the idea of a united landmass. The coelacanth is another fossil that contributes evidence for Pangaea. Initially thought to be extinct and only known from fossils, the discovery of live coelacanths in modern times has provided insight into how species distribution might have occurred when Pangaea existed. Since coelacanths are found in both the Indian Ocean and the Indonesian archipelago, their distribution is suggestive of a historical connection between land areas now separated by the sea.