What is a supercontinent that continued to separate?

The correct answer is: Pangea.

Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras, about 335 to 175 million years ago. It was the result of the collision of several smaller continents and microcontinents that had broken away from the supercontinent Rodinia about one billion years ago. Pangea was surrounded by a single ocean called the Panthalassa.

Over time, Pangea began to break apart due to the movement of tectonic plates. The first split occurred about 200 million years ago, when the North American and South American plates began to move away from the African and Eurasian plates. This created the Atlantic Ocean. The other continents also began to move away from each other, eventually forming the continents we know today.