And the giant land mass submerged in the southwest Pacific is also a step closer to being recognised as a separate continent in its own right if scientists get their way.
New Zealand (the country) sits on top of the 1.9 million-square-mile expanse which may be 94% covered by water but meets all the other criteria applied to each of the seven other continents.
Once part of the Gondwana super-continent which also included Australia, Zealandia is roughly the same size as the Indian subcontinent.
It is believed to have broken away about 100 million years ago, according to geologists, and sank between 60-85 million years ago.
As well as both the North and South Islands of New Zealand, Zealandia also includes New Caledonia, Norfolk Island, the Lord Howe Island group and Elizabeth and Middleton reefs among other territories and islands previously grouped with Australia in Australasia.
A paper published in the Geological Society of America's journal, GSA Today, says: "The scientific value of classifying Zealandia as a continent is much more than just an extra name on a list.
"That a continent can be so submerged yet unfragmented makes it (useful)... in exploring the cohesion and breakup of continental crust."
Mr Mortimer told TVNZ: "If we could pull the plug on the oceans, it would be clear to everybody that we have mountain chains and a big, high standing continent.
"What we hope is that Zealandia will appear on world maps, in schools, everywhere.
"I think the revelation of a new continent is pretty exciting."