Why is it possible to find fossils in Antarctica?

Because once the world was a pangea, meaning that all of the continents touch each other, which means that animals could walk around freely and when they started drifting apart, (continental drift) some were stuck on there to freeze and die.

Because Antarctica was once connected to the rest of the continents. When Pangaea was together, Antarctica was on the bottom and eventually moved down as the rest of the continents were made.