a mammal of an order whose members are born incompletely developed and are typically carried and suckled in a pouch on the mother's belly. Marsupials are found mainly in Australia and New Guinea, although three families, including the opossums, live in America.
n the sentence, "in" is a prepositional phrase, but you have to add the words "place of" along. Otherwise it would not count as a prepositional phrase.
