It is also the "youngest, thinnest and most submerged" of the continents, as 94 per cent of the landmass is submerged, the geologists wrote.
In the paper, titled Zealandia: Earth's Hidden Continent, the geologists argue that Zealandia has all four attributes necessary to be considered a continent.
Those attributes include "high elevation relative to regions floored by oceanic crust'', and the presence of three types of rocks (igneous, or volcanic; metamorphic, or created by heat and pressure; and sedimentary, or created by erosion).
The other attributes are a thicker, less dense crust than the surrounding ocean floor, and an area large enough to distinguish it from the category of microcontinent.
"The scientific value of classifying Zealandia as a continent is much more than just an extra name on a list,'' the scientists wrote.
"That a continent can be so submerged yet unfragmented makes it a useful and thought-provoking geodynamic end member in exploring the cohesion and breakup of continental crust.''
All but one of the 11 researchers behind the paper represent organisations based in New Zealand and New Caledonia. The 11 scientist is based in Australia.