Regarding biogeography, why are similar fossils of the reptile Cynognathus found in Africa and South America? 

 

Cynognathus is an extinct reptile which looked like a mammal . It had a short tail and limbs which were close to the body , meaning it was efficient in movement .The Cynognathus 's body with the limbs close to the body shows that it was not able to swim .

The inability to swim shows that the animal lived in only one area that was not divided by water . That is the case at the moment between Africa and South America . The theory of the whole land masses being connected in the Permian period comes forward . The earth was connected into one large land mass called the Pangaea . In the late Permian period , land masses started drifting away slowly . By the fact those fossils were found solely in Africa and south America suggests that the two continents are the most likely to have drifted apart last . This happened either before the animals went extinct or just after they went extinct showing that the two continents where somehow isolated from the others and their climate favored the development of Cynognathus . The harshness in climate led to their extinction .