Yeshive Bochers (Jewish divinity students) love to formulate difficult questions to their teachers. For example: How did an Australian marsupial like the kanguru travel to Mount Ararat and take his reserved seat in the Ark? Flying Quantas? Rabbi, how was that?
Rabbi Moshe Leib the Cohen Halberstadt has the answer. It goes like that: You know that there is a process called evolution in nature. Yes, Darwinian evolution. There are "initial", antediluvian animals that were in the Ark and survived the flood. There are other animals that were not in the Ark but evolved from the survivors. Now, is the kanguru an antediluvian, initial, root animal, or it evolved after the flood? The distinction is unimportant, the fact is that Australia is full of jumping kangurus, so it definitely must have been one or the other.
BTW, the kanguru meat is not kosher.