The fossil record indicates that at one time marsupials were common to both Australia and South America, but today most South American marsupials have become extinct. The most probable explanation for marsupials being common to Australia yet not very common to South America today is that Question 16 options: South American marsupials were displaced by placental mammals when a land bridge formed between North America and South America about seven million years ago. marsupials were able to flourish in South America because of its isolation from other land masses. placental mammals are less fully developed than marsupials when born and therefore have a better chance of survival after birth. South American and Australian marsupials interbred. marsupials can survive only in warm climates like Australia.
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Australia and South America were once connected via the supercontinent Gondwana, which began to break apart around 180 million years ago. This connection allowed marsupials to spread between the two continents. Show more…
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Sri K.
Marsupials are found only in North and South America and in the Australian region. Their distribution is a result of the breakup of the supercontinent Pangea into Gondwana and Laurasia 120 mya. The modern distribution of marsupials is therefore a result of the effect of ________. present abiotic factors present biotic factors past abiotic factors past biotic factors
John N.
Which of the following statements best explains how continental drift caused the uniqueness of Australian fauna before Europeans settled on the continent? Continental drift separated Australia from the other continents after both marsupials and eutherians evolved, but these marsupials underwent adaptive radiation and the eutherians went extinct. Continental drift broke the land bridge between Australia and southeast Asia, isolating marsupials on Australia and allowed them to diversify and occupy many ecological niches. Marsupials remained in Australia when continental drift connected it to southeast Asia. Eutherians went extinct in Australia after continental drift separated Australia from southeast Asia.
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