Continent with other islands in the Pacific into one continent called Oceania. This divides the entire land surface of Earth into continents or quasi-continents. The ideal criterion that each continent is a discrete landmass is commonly relaxed due to historical conventions. Of the seven most globally recognized continents, only Antarctica and Australia are completely separated from other continents by the ocean. Several continents are defined not as absolutely distinct bodies but as ""more or less" discrete masses of land". Asia and Africa are joined by the Isthmus of Suez, and North and South America by the Isthmus of Panama. In both
Australia (continent) Australia and New Guinea, and Bass Strait between mainland Australia and Tasmania. When sea levels were lower during the Pleistocene ice age, including the Last Glacial Maximum about 18,000 BC, they were connected by dry land. During the past 10,000 years, rising sea levels overflowed the lowlands and separated the continent into today's low-lying arid to semi-arid mainland and the two mountainous islands of New Guinea and Tasmania. The Australian continent, being part of the Indo-Australian plate, is the lowest, flattest, and oldest landmass on Earth and it has had a relatively stable geological history. New Zealand is not part