Are all the earths ocean basins less than 2000 million years old?

No, not all of Earth's ocean basins are less than 2000 million years old. While many ocean basins have formed and changed over the last 200 million years due to plate tectonics, some features, like the Atlantic Ocean, have origins that date back to around 200 million years ago. In contrast, older oceanic crust can be found in certain areas, such as parts of the Pacific Ocean, which can be much older, but the ocean basins themselves continuously evolve and are shaped by geological processes.