On the landmass that became South America

Question

Quizplus · Accepted Answer

A. Monotremes (egg-laying mammals) were present in South America, but they were not replaced by marsupials and early placental mammals. Instead, South America had its own unique marsupial and placental mammal fauna. 
B. Placental mammal migration from North America to South America began around 35 million years ago, not 5 million years ago. 
C. Many early placental mammals did become extinct in the Pliocene, but this occurred worldwide, not just in South America. 
D. Early placental mammals arose during the Cretaceous period, which spans from about 145 to 66 million years ago. So this choice covers a time range that is not specific to South America. Therefore, E is the correct answer as it includes correct information and correct timing for the evolution of placental mammals in South America.

On the Landmass That Became South America