Continent Continent A continent is one of several very large landmasses of the world. Generally identified by convention rather than any strict criteria, up to seven regions are commonly regarded as continents. Ordered from largest in area to smallest, they are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia. Geologically, the continents largely correspond to areas of continental crust that are found on the continental plates. However, some areas of continental crust are regions covered with water not usually included in the list of continents. Zealandia is one such area (see submerged continents below). Islands are frequently grouped with
Smallest organisms cetacean, which is also (as of 2006) the most endangered, is the vaquita. Male vaquitas grow to an average of around 135 cm (53 in); the females are slightly longer, averaging about 141 cm (55 in) in length. Duckweeds of the genus "Wolffia" are the world's smallest flowering plants. Fully grown, they measure only 300 µm by 600 µm and reach a mass of just 150 µg. Nanobes are thought by some scientists to be the smallest known organisms about one tenth the size of the smallest known bacteria. Nanobes, tiny filamental structures first found in some rocks and sediments,