How Did North America End Up With a Marsupial?

Marsupials, primarily found in Australia, have a rich history in the Americas. Fossil records show their origins in Asia, with significant findings in North America. Marsupials thrived in North America before going extinct, while South American marsupials diversified. The Virginia Opossum is the only marsupial north of Mexico today. Marsupials reached Australia when it was connected to South America and Antarctica. The decline of North American marsupials is debated, with theories suggesting competition with placental mammals. The opossum helps trace marsupial history.

What evidence suggests that marsupials once thrived in North America?

Discuss the theories regarding why marsupials are less common in North America compared to South America.