Zealandia (pronounced ), also known as Te Riu-a-Māui (Māori) or Tasmantis, is an almost entirely submerged mass of continental crust that subsided after breaking away from Gondwanaland 83–79 million years ago. It has been described variously as a submerged continent, continental fragment, and microcontinent. The name and concept for Zealandia was proposed by Bruce Luyendyk in 1995, and satellite imagery shows it to be almost the size of Australia. A 2021 study suggests Zealandia is 1 billion years old, about twice as old as geologists previously thought.By approximately 23 million years ago the landmass may have been completely submerged. Today, most of the landmass (94%) remains submerged beneath the Pacific Ocean. New Zealand is the largest part of Zealandia that is above sea level, followed by New Caledonia.
With a total area of approximately 4,900,000 km2 (1,900,000 sq mi), Zealandia is substantially larger than any features termed microcontinents and continental fragments. If classified as a microcontinent, Zealandia would be the world's largest microcontinent. Its area is six times the area of Madagascar, the next-largest microcontinent in the world, and more than half the area...Wikipedia ()