The diagram shows South America, Africa and a Mesosaurus, a reptile that lived 300 million years ago.

Question

The fossils of this reptile were found only on the continents of South America and Africa. If this reptile could swim across the Atlantic Ocean, its fossils would have been found on other continents. What argument can BEST be made using this diagram?

A.
Earth's continents were once closer together.


B.
Earth's plates are in the same location today as they were millions of years ago.


C.
Earth's surface was once under water.


D.
Earth's landmasses continue to erode causing animal populations to be separated.

Answer 1

The best argument that can be made using this diagram is:

A. Earth's continents were once closer together.

The presence of Mesosaurus fossils only on South America and Africa suggests that these continents were once connected or much closer together, allowing the species to inhabit both landmasses. If the Mesosaurus could not swim across the Atlantic Ocean and its fossils are found exclusively on these two continents, this supports the idea of continental drift and that the continents were once part of a larger landmass.