Pangaea was a massive supercontinent that formed between 320 million and 195 million years ago. At that time, Earth didn't have seven continents, but instead one giant one surrounded by a single ocean called Panthalassa.
The explanation for Pangaea's formation ushered in the modern theory of plate tectonics, which posits that the Earth's outer shell is broken up into several plates that slide over Earth's rocky shell, the mantle.
