Australia (continent) of the continent of Australia, but of the separate, submerged continent of Zealandia. New Zealand and Australia are both part of the Oceanian sub-region known as Australasia, with New Guinea being in Melanesia. The term Oceania is often used to denote the region encompassing the Australian continent, Zealandia and various islands in the Pacific Ocean that are not included in the seven-continent model. Papua New Guinea, a country within the continent, is one of the most culturally and linguistically diverse countries in the world. It is also one of the most rural, as only 18 percent of its people live
Continent as "New Holland, an immense island, which some geographers dignify with the appellation of another continent" and the "Oxford English Dictionary" was just as equivocal some decades later. Antarctica was sighted in 1820 during the First Russian Antarctic Expedition and described as a continent by Charles Wilkes on the United States Exploring Expedition in 1838, the last continent identified, although a great "Antarctic" (antipodean) landmass had been anticipated for millennia. An 1849 atlas labelled Antarctica as a continent but few atlases did so until after World War II. From the mid-19th century, atlases published in the United States more commonly