Now recognized in international law, Zealandia — the continental shelf and margin surrounding New Zealand — is vast and worthy of inquiry. However, we disagree with attempts to recharacterize it as the 'eighth continent' (see Nature http://doi.org/b2fk; 2017).
Zealandia has been extensively studied since 1895 (see W. H. F. Smith and D. T. Sandwell Science 277, 1956–1962; 1997). Such studies underpinned New Zealand's successful application to the United Nations to extend the limits of the continental shelf and its economic exclusion zone (see go.nature.com/2mbwmb).
Continents are defined by the Oxford English Dictionary as continuous terrestrial geographical features (“as distinguished from islands, islets, or peninsulas”). Geologists do not define continents: instead, they characterize the types of crust and delineate their geological features. By this definition, Zealandia is not a continent. Indeed, it is 94% continental margin with an extended shelf.